Underwear No More

After decades of seeing superheroes wearing their underwear on the outside, comic artists have finally realized that it looks too gross.

Wolverine and his blue underwear on his signature yellow outfit.
A much more pleasant-looking outfit of today.
Batman, who doesn't love the dark knight?
Got milk?

Except for one guy...

The man of steel himself still stands proud in blue spandex, red cape, boots and of course, underwear.

Now this is what I'm asking, and this is what I'm wondering - why did superheroes wear their underwear on the outside?

After years of contemplation, I still haven't figure it out entirely...

Maybe, just maybe, that's what makes them extraordinary...