Sneider's kind of a prick, but he's right. Fans on Twitter could stand to be a little less worked up over what superhero movie they prefer. Some of the behavior gets downright embarrassing.
When I see a memorial post for a man and his 13 year old daughter who tragically lost their lives and the comment section is bombarded with "Release the Snyder Cut!" and angry Superman gifs, I realize some people need to step back. And this is not just DC. The Star Wars fandom has also reached embarrassing heights the last few years, and many Marvel fans can be just as ridiculous, it just doesn't come up that often since that franchise is much more successful and thus has less moments of controversy that cause people to act like clowns online.