Well, if you compare it to the incredible amount of gods and godesses and other figures we've got in our own mythology, there really aren't that many. I mean, there are about a couple less than 40 legendaries in all as of now in Pokemon, which seems like a lot but really isn't XD
however, I see where you're coming from. There are quite a lot of legendaries in D/P/P, having it be more spread out would be nice too. That, and the legendaries do all seem to be following a pattern, basically either a sleeping giant sort or a see-it-once-then-chase-it-around-the-country sort without much type variation.
Also. The insane amount of psychic-type legendaries! variety plz lol. I wanna see a Poison, Fighting, or Bug legendary (that works), ideally.