Marvel and Star Wars aren't fine--the writing is execrable whenever they aren't outright plagiarizing something else.
Star Wars was schlock meant to sell toys that just happened to become huge. Marvel is pretty much just straight up garbage across the board (some characters are interesting--the stories and world though are pretty uniformly trope-ridden crap).
Modern movies also have the problem that a lot of their revenue comes from overseas--China in particular. They can't risk having writing that is either too subtle for a foreign audience or cover themes that might get them banned by the government.
Thus we get Michael Bay syndrome--spectacle after spectacle and the minimum writing necessary to connect them.
(To be honest--this is nothing new to Hollywood--Michael Bay can trace his roots the whole way back through "Towering Inferno" to "Noah's Ark", etc.)
I'm sure alot of this can be traced back to Manga roots.
When you get down to comic books and animations, the market forces aren't quite so vicious and your "10% okay vs 90% of everything is crap" doesn't get so filtered out. Consequently, you get more of the standard curve--some stuff is bad, most stuff is average, some stuff is good, and a few gems poke up every now and then.
"How do you have a problem with this, but Marvel or Star Wars is fine". I wasn't sure how to answer that at first, but I think your comment solidifies it. I can accept ridiculous and unrealistic scenarios as long as they are fun, and held together within an equally ridiculous world.
Theres a fine line between something that is clearly a dramatisation being frustrating or just fun.