Squats and deadlifts are less isolating for the butt...they're less "handy" to do at home, and if you don't know how to do them, when you use any kind of useful weight it's easy to hurt yourself. Plus you require a certain degree of flexibility to do deadlifts esp fo lifitng a bar off the ground - assuming you even have a barbell at home.

I think they're awesome exercises, but less relevant than lunges for the point of this post.