"Again, stop missing my point."
You first. And just to be clear I don't care which parent it is that stays home (or both if that is feasible).
"I'll be a better parent if I get to do what I want to do."
All the rationalizing in the world about how it's really good for the child for you to go out and do what you want to do... it's still just rationalizing. It's a long life. If you can't take off a few years to be with your children when they need it most then you don't value children enough to be having them. Just rent them so they'll only be around when you feel like lavishing some attention on them. Then the rationalizing to ease a guilty conscience won't be necessary.

Oh and just to be clear on something else, when you hand your two year old off to the nanny so you can go off and be "fulfilled" all day - that child knows precisely what their value is to you - secondary.