Based on probability, there's absolutely no reason why there wouldn't be infinite such worlds. Based purely on math, is it possible that within an infinite set there exists only a finite subset meeting a certain condition? That's absolutely possible. For example, the set of natural numbers is infinite. The set of all natural numbers less than 100 is finite. It's a finite part of an infinite set.
If the chance that a given world in the set of infinite universes can support human life is a constant other than zero, then there must be infinite such worlds. However, what if there's some outside condition? What if worlds that can support human life are only possible because God created them like that, and there is only one God? If God chose to create 100 such worlds across the infinite universes and no more, then there are no more. There are other possible such conditions, God is just the easiest one to understand.