I always liked that because a single character could never get every feat(perk) so it upped the replay value with different characters and character types, and some really powerful abilities took longer to get to but once you were able to get them they were very rewarding.
Oh, also, many feats didn't require other feats, but rather a certain ability skillset...an example of this in TES would be needing to have a certain rank in a weapon skill before being able to access an ability related to that weapon.