Why apply to more? Scattershot is not the way to apply to universities. Pick the few best suited to you, focus your energy and time on those. Additional applications beyond getting into one of your top three is just wasting time and money on applications.
Now, if you don't have a great shot at your top three, and you are hoping somone surprises in the scattershot, let's you in and it will just be an adventure from there go for it. But there is nothing wrong with only applying to a handful of schools and you shouldn't feel bad.
I applied to and got into one of my top graduate schools twice but had to back out when they offered no aid and it was going to put me 100k in debt over 2.5 years.
The path not taken I suppose...