I don't honestly see a problem with either of those things. Fighters are melee masters. Their basic attacks SHOULD be better than anyone else's. And if the warlord has a party of magical, ranged, or agile characters, yes, he SHOULDN'T be granting MBA's then.
Why is a Fighter or Barbarian more of a "melee master" than a Battlemind or an Avenger? These are all melee characters. And the monk who is supposedly the best trained class in unarmed combat, needs a feat to take a good opportunity attack? Or when the warlord says "you attack that guy!" the ranger knows exactly what to do, but the monk has to stop and say "sorry boss, I don't know how to do that outside my own turn"?
I just don't see a fluff explanation as to why all classes shouldn't have a competent melee or ranged basic attack feature, depending on their specialty, nor do I see a game mechanical or balance reason why this shouldn't be the case.