The most famous character from Fantastic Comics was probably Stardust (I've mentioned him a few times in the past), and in this story from #7, it's demonstrated why:
Because he and his enemies followed a truly special kind of logic.
For the record, while it would be very bad for the world to stop rotating (the H.G. Wells story The Man Who Could Work Miracles has a depiction with at least limited realism in it, though the means through which rotation was stopped didn't even bother with realism, which is just as well), it wouldn't be the sudden cessation of gravity.
Which you should probably be at least vaguely, intuitively aware of, or at least figure out from looking up gravity on Wikipedia.