That would be a good idea,it's what you have on Youtube accounts (the games i've played bit).But they are working on the new Armor Games website so they just might collect your idea if this post gets enough publicity! Good idea!
There are over 2000 games on AG. I've played over 1400; to have the highscores would take to much space. But it's an interesting idea; it could be a fixed link to it at the profile.
I just did post in that category, I dont see how it would take that much space, aren't they hosted at AG servers? if that the case it just a matter of adding another view to it, either way it's just a string, assuming 10 digit scores times 2000 games it's just 20k extra per profile, and that's a extreme case