A stomp is really nothing but a forward thrust kick whose direction is largely aligned with the direction of gravity, i.e. forward thrust aimed a lot lower and closer to the body. If it's any more dangerous than what you normally think of as a forward thrust kick, it's just because it's easier to drop the stomp than the forward thrust. You're not bringing down the entire weight of the body unless you're actually airborne when you thrust out one or both legs, i.e. jump and stomp/vertical drop kick.