CancerMan says:
I guess I don't see the issue between having two lists to choose from, when you are restricted to a handful of spells. When it comes time to pick a 3rd-level spell, for example, do I choose Lightning Bolt or Revivify? Counterspell, or Mass Healing Word? Once I make that choice, I have to wait until I gain another level to either swap out that spell for another, or pick a new spell if I'm able.
Versatility is a big one. Also, in this case a concern is metamagic. They may be able to pick fewer spells, but they can stretch out what they do a little bit more. In my opinion, having versatility IS power in its own way.