Ah believe me, I can understand that also. People go to the movies to escape from reality for a mere few hours, so many people don't want to see "real life" played out on the big screen with all the negativity that they already encounter in the real world. Especially in a superhero film like you said, because these are supposed to be characters that people should aspire to be, not characters that already remind us of ourselves.
However, I feel that's precisely why characters such as Batman and Iron Man tend to be quite popular, especially with younger crowds, because they are "flawed". Batman's motivation to do good essentially stems from revenge for what happened to his parents, while characters such as Superman and Captain America already possess an innate goodness that isn't motivated by revenge nor anything else other than simply wanting to try and do good. In our society, many people always feel there's a catch to something, so when we encounter people and see these characters that are intrinsically good and amiable with no strings attached, we have the propensity to question their intentions. I felt this was accurately conveyed in the scene in BvS that showed Supes doing acts of goodness, while people debated the need for a "Superman" and what they feel his intentions are based on ourselves. During that scene, there was a quote that said we as people have the tendency to project ourselves onto others, so if we feel we're flawed and are capable of a certain thing, then we tend to project this onto others when it actually might not be the case. It goes back to what I mentioned in my previous post about many people not liking to feel like someone else is above them. And that quote was then followed up with another quote with someone saying that perhaps he's neither a God nor a demon, but is simply a guy who is just trying to do the right thing. The fact that Supes at the end of BvS was rejected by many, but still possessed the strength and valor to sacrifice himself for the safety of the very people that rejected him gave me all the hope in the world. I like the fact that starting with MoS, Snyder made it a learning journey for him. People are learning about him as much as he is learning about himself. He doesn't put on the blue and red suit and automatically knows what to do in every situation. Jonathan Kent's quote in MoS before his death even alludes to that, where he said that he and Martha have been doing the best they can and have been making it up as they go along, so perhaps their best isn't good enough anymore. How we handle adversity tends to be a testament to show what we're really made of. I felt Supes demonstrated this perfectly in both MoS and BvS.
Despite how cynical our society can be, I like to believe that deep down, people know what the "right" thing is. Sometimes our brains are wired and conditioned to think a certain way though.
You're right though, because that's the beauty of opinions; they're neither right nor wrong. Someone else's opinion is no more valid than yours, and yours is no more valid than theirs. It is indeed interesting to hear different viewpoints.