I genuinely liked BvS and appreciate Snyder going for something different; I hope they actually release the Snyder cut. If I wanted just more of the JL/JLU style, I’d rather they make more seasons of that instead of restricting themselves to the movie format. Young Justice kind of scratches a similar itch as well, so I’m down for more adaptations that don’t strictly adhere to the source material.
This is always the rub when discussing Snyder, because obviously, a film adapting a comic is necessarily going to be different from the source material. So usually when I discuss not liking Snyder's direction for a DC-based film universe, the line is of course "Oh you want it exactly like the comics/TV shows."
No, I want a good movie.
More than that, if you're labeling something as a "DC movie" and using DC characters, you impose on yourself certain expectations and limitations. If that's disagreeable, the avenue to make a new IP is always open.
I've read a lot of DC comics. There's a lot of great Elseworlds and alternate universe interpretations of Superman and Batman. But what Snyder and WB positioned the DCEU originally as wasn't an "Elseworlds." It was their main cinematic universe to take on Marvel, featuring the first shared-universe versions of Superman and Batman on-film. All this to say, among many other things, the "primary" portrayal of Batman doesn't kill. Period.
WB is giving itself a lot of fan-leeway going forward by ditching the MCU blueprint and focusing on standalone Elseworld-y tales like Joker. And they're certain to earn less of my ire after ditching Snyder.
With any hope, this Snyder Cut will by the dying gasp of his influence on DC films going forward. But he'll probably be a fucking producer or something fucking things up behind the scenes til the end of time.
That’s fine, it’s okay to not like things that someone else might like.
You’re kidding yourself for thinking Snyder is the first to break Batman’s no-kill rule, though. Batman has been killing in the movies since Burton’s Batman. Even Nolan’s Batman killed.
As for compromise: rarely does a movie make it from page to screen without some manner of compromise, sometimes good and sometimes bad. We can’t know whether the movie would have only worked as a two-parter as originally envisioned or if Snyder believed changing it to a single movie was better for it. What we do know is his vision was directly contradicted with studio intervention, by choice or otherwise, and if he feels up to the challenge now of trying to finish what he began, I’m all for it. We already have precedence for a similar analogue with The Donner Cut of Supes2, so why not?
I'm begrudgingly accepting of this because, as you said, it's a new cut of a film closer to the original intentions of its director. No matter what I will always respect that and advocate for creator-controlled projects in general.
But man, I thought this dude was done with DC. I got my hopes up.

As for "Batman has killed before," it's actually one of my major knocks against Burton's Batman (especially in Batman Returns, where he literally hands a goon a bomb right before it goes off, and I think he toasts some other clowns with the Batmobile too.) But there's something different from that cartoonery, and not-seeing a bunch of offscreen ninjas blow up (Batman Begins), compared to Batman strapping AK-47s to every goddamn vehicle he has, breaking dudes necks like it's nothing, and deliberately blowing two goons to smitherenes on-camera.
Maybe I'm the only one in the world who sees the difference between the situations, but it still bothers me.
Nolan's Batman wasn't "perfect" as an adaptation either, particularly in Rises where he fucks off for ten years because he's sad his non-girlfriend died, but by that point Nolan had earned the right to steer the character in non-canon ways.