Originally Posted by sf2
Why just on the trunks? What are the reasons superman wearing the red boots? He can’t fit his shoes in to disguise. Man doesn’t wear red boots. It looks tacky. Why red cape??? It’s neither for protection nor flight. It’s troublesome in fact. Why dark blue tights??? Why not white, black or gold???
Simply put, To explain the suit / the trunks is wasting the precious screen time. Because people will still complain and not buying the explanation.
Did Batman Begins waste screen time? Better yet, what about in the Avengers when the retaining of Captain America's stars and stripes uniform was explained by Agent Coulson in a single scene which even concluded with:
"Aren't the Stars and Stripes a little... Old fashioned?"
"With everything that's happening, the things that are about to come to light, people might just need a little old-fashioned."
That one little exchange says a lot about what the writers were trying to communicate to the audience in trying to give them reason to open up to such an ostentatious outfit. A little context goes a long way and there are innumerable examples to back up this point in case it's still not clear. Just because its hard as hell to give Superman's classic costume a legit and elegant context doesn't mean it's not the solution nor wouldn't at least help.
Also, mind you, what you're suggesting as as waste of screen time is exactly what happens in MOS when we find out the suit is kryptonian; again, the controversey being that the designers felt the classic design, as it was, was not "alien" enough and didn't fit with the context they went with. So they altered it. Apparently aliens don't wear trunks.