You make a good point. It's possible they aren't sports.
Most wrestling is acting anyway. Most ice rink events are clearly art (dance). Only the speed skating has a reason to consider itself a sport. Diving certainly isn't a sport, it too is an art form.
Gymnastics is questionable. It might be that the definition is incomplete, I'd like to think so. Judges giving scores because the competitor did something nicely is what makes it questionable; they should only be there to ensure it is done correctly. So despite having not considered it before, I think you are probably right, it seems not to be a sport either.
At least with the other two the judges should only be deciding who scored the most hits, falls, whatever. They ought not be giving points for nice footwork, a pretty hairstyle, or a good bounce up again.