The reason why Space powers might be harder to come up with is that Space is about physics. So to come up with cool powers you need to know how laws work what they do and how. Understand the implications of laws. Maybe that's the case, at least that's what I think it is.
I mean, my reasoning is that it’s the opposite- We understand Space way better than Time, so we can apply imagination to Time a lot more. With Space you kind of know what you’re getting into.