I hate this opinion because Batman and Superman are both, it is what makes them unique. There are many no-power/low power heroes, but the reason Batman is so famous is because they put him through internal conflicts more often than not. The Riddler is a battle of the mind, Scarecrow is all about making Bruce come to terms with his fears, and Joker has increasingly been targeting Batman in ways to break his mental state. The villains typically say something about Bruce as a person, showing how broken he is, but also why he is above them.
they are both because a) there's an exception to every rule and b) you still need both.
take the hulk for example, he still has his internal jekyll/hyde conflict, just with more demolition involved. without that he would just be a green wrecking ball of low intellect.
scarecrow/riddler/joker playing mindgames with batman is still an external conflict, remove those and the conflict is gonna with it. and not every conflict is physical, sherlock holmes having a battle of wits with moriaty is still an external conflict - otherwise holmes would just chill, play violin and probably give himself a golden shot simply to escape the sheer boredom. however superman sitting in the fortress of solitude pondering the meaning of his humanity isn't something you can just remove or is caused by an adversarial force. that doesn't mean supes can't smash shit occasionally if need be, but the power is part of the inner conflict too - all that power and how to use it?
Little kids like Superman - bright colours, cool powers, good and heroic. Older kids and those adults who still read comics mostly no longer believe in purity, altruism, unironic heroism. I'm not sure anybody surrounded by funkopops can. So they like Batman. Batman is broody, edgy, driven by motivations that they aren't embarrassed by (revenge, trauma). Batman is "cool".
eh, dunno. teens are edgy because they're teens. kids are more "pure" and naive, superman potentially leveling cities trading blows is great action for them, adults having more life experience would see the toll of human lives and damage etc.
I'd say people go with batman first because he's simply easier "to get" and his fight is usually "some of gotham's rogue gallery is up to no good and needs to be stopped". for superman that wouldn't really work, what he has to deal with and how he does it scratches another itch. I wouldn't call it immature, just people having different tastes and one is more mainstream (and it doesn't mean someone can't like both for different reasons and that they're different in the first place). or in another example, people rather watch the hulk smash stuff than bruce banner/hulk have a philosophical discussion about split personality and the dominance of either..
as for the mentally stunted adults, keep in mind those are the same people who just emancipated the punisher - if it was about living out their revenge fantasies they could've just made him punch some nazis and exchange the skull for an antifa logo (but then he'd still be a cis white male, so...).
the eyebrow raising part is rather that they started glorifying villains for some weird reason, either because it's one of their pet genders/races/minorities or some weird cognitive dissonance where only the bad guy is allowed to do bad things - or anything at all - which on some level makes him the "good" one in terms of interesting for actually doing something... a neutered hero that doesn't do anything heroic because he isn't allowed to or doesn't fit their retarded notion of the world is simply boring, and even they know that subconsciously. it's the same reason their writing is so awful and schizo, they can't have the "good" guy do bad thing because he's "good", but the villain can't be too "bad" because it could trigger someone and depending on the hero would be sexist/racist/whatever. and every hero is only as good as the villain (or the struggle he has to overcome, but modern heroes have no struggle since they're already perfect).
I'll say this. Whilst the writing for Superman in various media has often been questionable, the casting has been exemplery. Tom Welling, Brandon Routh, Henry Cavill... they're all superbly qualified for the role in both looks, charm and empathy. Routh and Cavill were both cheated out of what they deserved honestly. At least Tom Welling got a really good run as Superman.
people doing dean cain dirty as usual... at least he got prime teri hatcher as lois.
