Both Nolan and Snyder are different artists with completely different artistic visions for the DC Universe. Because of this, I don't like to compare the two. Neither are necessarily supposed to be retellings or representations of the comics. They may allude to storylines, but are their own stories and universes, thus should be respected as such. For example, we wouldn't compare the Injustice universe to the Flashpoint universe. Both are different universes with different interpretations of characters and storylines, and should be treated as such. Both can be appreciated.
That being said, I personally prefer Nolan's vision. It was crafted far more meticulously and purposefully. I think it understood the characters at their core and branched to create it's own universe from there. While I respect that Snyder had his own vision, and some ways didn't get to see it through, he completely misunderstood why these characters are beloved, and who they are at their cores. Dark universes can work. Dark interpretations can work. Snyder's artistic vision can work. Completely missing the mark on who these characters are cannot.
“It’s a cool point of view to be like, ‘My heroes are still innocent... My heroes didn’t commit any atrocities.’ That’s cool. But you’re living in a f***ing dream world.” I know this is a well worn discussion and territory, but I feel it's important to bring up (I'll try to make it brief though). This quote, and entire video, made me realize that Snyder lacked any understanding of who these characters are and why they are beloved. I'm sorry, but Batman or Superman or whoever doesn't kill. I can understand wanting to take a grounded, realistic approach, but stripping these characters of their most basic and core values means you don't understand them and don't take them seriously. Stripping a character of their values is just as bad as stripping them of their costumes (hint hint Brian Singer). You can have a realistic world with these characters and still treat them with respect. Yes, these concepts of not killing people are absurd and unrealistic, but that's the point. People read comics to escape from reality. To be transported to a place where world-ending problems can be solved by a single person. It's a nice escape from the threats we face as a society on a regular basis. And the thought that any one of us walking around could have a double life, and be that person inspires people to stand strong and hold their values like the heroes they read about.
On top of that, it's not that the fans aren't on board with a gritty or dark universe. It's not that they have unrealistic expectations or beliefs. Some of the darkest characters and storylines in the DC Universe are the most beloved (ie Death in the Family, Injustice, Identity Crisis, etc.) It's not that DC fans don't want a dark adaptation, it's that they want their films to do justice to the characters they portray. In fact, the boycotting of Teen Titans Go! proves it (which I have opinions on, but will save for a later discussion).
I was a fan of Snyder, and was willing to support his vision even though his films weren't very good in my opinion. But his clear misunderstanding of the characters, disrespect, and disregard for the fans who try to explain this to him made me lose faith. I'm sorry, but I don't believe he was the man for the job. I know it's easy to point to the success of Watchmen and say he's a talented fan who does just to the comics, but that film was pretty much a panel for panel recreation of it's already phenomenal source material. I, personally, am unable to give him the praise for that film's success or quality. Especially seeing what he's crafted on his own with nothing to base his stories on.
I know I've kind of rambled on and went of topic, but I think it might be of interest to some people and still relates to the original question. Have a nice day, everyone!