It's an easy shorthand. The universe started with his set up and followed his aesthetic until it collapsed utterly.
I don't know what you mean by that. First of all, he wasn't the exclusive creator; David S. Goyer and Christopher Nolan were involved with
Man of Steel too (though Nolan's involvement was fairly cursory, I think). Second, I don't agree that other directors' films followed his "aesthetic," and in any case, what the heck does an "aesthetic" have to do with the writing decisions made in those films, the plots and character arcs, the things that matter to what a film is actually
about rather than merely what it
looks like?
Some people similarly refer to the Arrowverse as the Berlantiverse despite his having very little to do with the shows beyond their inception.
Now, that's an absolutely nonsensical comparison. Of
course Berlanti was involved; he was the president of the production company and thus participated in the creation of every series in his company's stable, which is what production company heads
do -- co-create shows, then supervise their individual showrunners' work while moving on to develop the next season's shows. He was a co-developer, pilot co-plotter, and executive producer on
every series in that continuity (as well as
Titans), rather than being completely phased out 20% of the way through like Snyder was. Good grief, it was his company that made the shows, so he's a better analogy to a Warner Bros. studio exec like Jon Berg or Peter Safran than a director like Snyder. No, he didn't personally write or direct most of those series's episodes, but he was the
boss of the people who did, the one who had final approval over their decisions, so it's ridiculous to say he had no involvement. He was just as involved in the Arrowverse as Alex Kurtzman is in
Star Trek, because that's how production companies work.
Warner Brothers wanted it to resemble the MCU thinking that would automatically equal success and it backfired on them rightfully so. The changes they demanded were idiotic and failure was the inevitable result.
No. It's the "cinematic universes" that tried to copy the MCU that failed, e.g. the Mark Webb Spider-Man films or the Tom Cruise
The Mummy that was supposed to launch a new Universal Monsters franchise, because they forgot that Marvel started out by prioritizing the individual films with the interconnections being an optional, secondary element. They forgot that the whole doesn't matter if the individual parts aren't strong in themselves. They tried so hard to make their films prologues for what came next that they failed to make them good in their own right, and so the series flopped before they managed to get any more films. The studios assumed they were
entitled to do ongoing series rather than realizing they had to
earn that by making the individual films good enough that people would want more. And this was
Batman v Superman's mistake as well -- it's more an extended teaser for
Wonder Woman and
Justice League than it is an actual story in its own right. The series didn't begin to work until they stopped misdirecting their attention to the future and started prioritizing each individual film's needs. Because you can't do your current job well if you're only thinking about the next job.
And it's silly to call the post-Snyder DCEU films an "inevitable failure" when there were ten of them released over the course of six years, a longer run than the series had
with Snyder. Of all the cinematic superhero universes, I believe it was the longest-running one other than the MCU and X-Men.