Why is the "multiverse" idea so hard to accept?

There's been a lot of angst lately about the separation of the DC Extended Universe of movies from the DC TV universe of shows, most of them featured on the DC....I mean, CW Network. So much that Willa Holland from Arrow spoke out about it publicly and lit a bit of a fire under the whole subject:

Holland further complained about how Task Force X AKA The Suicide Squad had been done on Arrow first and it was "taken away" from them by the movies. 

Ok, we need to clear some things up about how DC Comics actually works. For starters, it believes heavily in the multiverse concept, the idea that there are parallel universes that are similar to each other with persons, places and even events, but just different enough to be not identical. It's a staple of DC Comics and anyone that watched The Flash this season got a crash course in just how crazy the whole thing is (and based on the season finale is likely to get even crazier). 

Now, understanding this idea and applying it to the DCEU and the DCTV Universe, Holland is already wrong about the Suicide Squad being taken away from them. The version of Task Force X that we saw in the second season of Arrow under the command of Amanda Waller is on a different Earth in a different universe than the one we are going to see in the movie Suicide Squad on August 5th. If DC wants to, they can go back to the Suicide Squad they used in Arrow again if they want to, even with the movie coming out. 

To be fair, if WB wanted to use the Suicide Squad again in the DCTV universe, it wouldn't be this exact group again due to events in the last two seasons of Arrow. 

What this allows DC to do is not get locked into continuity issues with the movies and the TV shows. Greg Berlanti, Marc Guggenheim and their people can keep doing what they are doing with Arrow, The Flash, Legends of Tomorrow and Supergirl, now on the CW starting this fall, while Geoff Johns, Jon Berg and their people can follow their plan with the DCEU, neither group having to worry about what the other one is exactly doing. 

So why is this a problem for some people? Well, there might be a few reasons: 

This is the DCEU's second movie and yet it's gotten enough scorn and hatred from people to get others thinking that the DCEU is in major trouble. So now we live a world where a movie that makes $872.2 million worldwide puts an entire franchise in major trouble. Sure, that makes sense. 

It's been more than two months and people still won't shut the hell up about how "horrible" Batman v Superman: Dawn of Justice was. The arguments are getting tiresome at best, but the negative buzz isn't going away from the bloggers and writers either:

Putting aside my own hatred and irritation of this crap for a second, there is a belief among many that after two movies, the DCEU is in crisis mode and in need of saving already......which is funny because nobody said that in 2008 about Marvel after The Incredible Hulk, the second Marvel Cinematic Universe movie, only made $263.4 million worldwide. I digress. 

Since people believe the DCEU is failing and DCTV is currently seen as thriving, this might be a big reason why people are clamoring for a crossover because they want the tone and setting of The Flash and Supergirl to go into the movies and "save" them. This is made pretty evident when you look at it across the Internet: 

Now that last one is about The CW's announcement that they are going to be casting an actor to play Kara Zor-El's cousin, Kal-El(Superman) in the second season of Supergirl, and outside of Tom Welling being an overwhelming favorite by the fans to play that role due to his Clark Kent portrayal in Smallville for so many years, people are also suggesting Henry Cavill, the actor who plays Superman in the DCEU. It could fit, as it was established in Season 1 of Supergirl that her Earth and universe are not the same as the one that Arrow, The Flash and Legends of Tomorrow are in. 

The thing of it is, is that if you put Cavill as Superman on the Supergirl show, then you open a huge can of worms that both sides will have to deal with. When the Justice League comes out, Supergirl fans might want to see Gal Gadot's Wonder Woman, Ben Affleck's Batman or Jason Momoa's Aquaman on the show at some point. Naturally though, since Supergirl has already had a multiverse crossover with The Flash and since all four CW DC superhero shows will be having a major crossover with each other this fall, people will probably want to see Ezra Miller, the DCEU Flash, go up against Grant Gustin the DCTV Flash. 

Both Grant Gustin and Ezra Miller have portrayed Barry Allen AKA The Flash this year and both will portray him again for the foreseeable future. 

Of course, Flash cast member Tom Cavanagh has been outspoken about that subject himself: 

For what it's worth, Cavanagh is right about Gustin's acting chops. He's been phenomenal as Barry Allen on The Flash and could potentially do very well in the same role on the big screen, but why lock yourself into that as either the DCEU or the DCTV Universe? Justice League is shooting now, which means that if Gustin were to be cast in both, his schedule would be beyond daunting between the movie and the third season of The Flash premiering this fall. On top of that, how would Justice League affect what is happening on The Flash show and the DCTV Universe in general? How about vice versa? 

It's much easier from a business and an aesthetic standpoint to treat the DCEU and the DCTV as multiverses so as to allow both the creative freedom and storytelling range to do whatever they want without being locked into what the other is doing. Marvel TV is essentially doing the same thing with the MCU and its TV shows Agents of S.H.I.E.L.D. on ABC, and Daredevil and Jessica Jones on Netflix. Even though all of those shows take place in the exact same universe as the Marvel movies, they are all still allowed the latitude and range to tell their own stories without being completely dependent on what the other is doing. That works for Marvel because none of The Avengers have TV shows, while Barry Allen, a charter member of The Justice League has his own show. With that in mind, the multiverse idea makes even more sense because anything Barry did in the DCEU would directly and immediately affect what he did in the DCTV Universe, shackling both universes together without choice for continuity sake. 

As many fans believe that a directly shared universe between movies and TV is exactly what they want, they should be careful what they wish for. If you make it so that both universes are completely shared and crossed over then critical events that happen in one will affect the other and it could affect how you watch both. You'll have to pay attention to the shows even more than you did before because what happens there will affect what happens in the movies and vice versa, and you'll be relying on two different teams of people, one for movies and one for TV to completely get on the same page with release dates, schedules, plot lines and characters to make it all work in harmony. You might think you want that, but something would definitely be lost in all that work and it would likely be the freedom to tell an uninhibited story on either TV or the theater screen or both.