That's kinda like saying an Epic Feat slot is boring because you only get to pick it once, even though that pick might be for Epic Spellcasting. Acquire Extraordinary Ability/Class Feature/Feat is free license to pick from the entirety of existence with regards to printed monsters...and even if you don't start the game with them, you can just go on a snack tour immediately. There are a lot of low-CR monsters with some stupidly powerful abilities if used in concert.