I think the reason people say they couldn't write a time travel plot is because they think about time travel for five seconds and don't come up with a plot right there.

It's rather easy to come up with plots that require backwards causality and time travel (and psychologically realistic characters, for that matter) if you devote only slightly more cognitive effort to it, such as making it into a hobby or pastime rather than a once-off throwaway thought. It looks Impressive, in the same way that memorizing an algorithm to solve a Rubik's Cube is Impressive.