It can be, yes.

And yet, there's a difference between, say, a 30% inheritance tax and a 100% inheritance tax. The 100% tax means that you cannot leave anything to your children. The 30% tax means that you cannot leave all of it to your children. One is more prohibitive (and therefore infringing) than the other.

And also the line that prevents you taking the freedom argument to it's logical conclusion that murder is acceptable.