Title say it all. I recall reading someone's post about not liking characters that have external powers, it was to the effect of "What's the point of liking a character if anyone can wear the suit?" and that really resonated with me personally. I'm a huge Spectre fan but I strongly dislike the Post-Crisis Spectre because the powers are not a part of Corrigan's spirit (it's an external entity or some lame bugger) & basically any schmuck can obtain the power.
Similar with Green Lantern, I acknowledge that the wielder of the ring is "chosen" because of their willpower, however outside of that that character doesn't have any superpower at all. I put "classic" in front of Iron Man because I've heard with the latest incarnation, Tony somehow placed the technology inside his body so the suit is a part of his physiology now, however prior to this despite the character's genius intellect, without the suit he can't go on any adventure or stop villains (despite his wealth) at least not on the scale that the suit would enable him to do so.
Wouldn't it be more interesting if the character gained that power via skills (be it super-science or magical)? For me, I prefer characters & heroes who derive their powers either due to their biology, an accident that gives them powers, or it's skills they have acquired. I just don't see the appeal of external-based superpowered heroes.