> Why is that almost all the super-heroes have their arch-enemy in their nearby locality.

Well, it would be silly to have an arch-nemesis that lives on the other side of the planet where you are never going to bump into them...

> They also share the same trait.

Well, it would be silly if a character with super powers was battling a mere-mortal, or a god. I guess that is why I always had a problem with Superman vs. Lex.