A handshake? That makes a professional? That defines it?
Actually, yes. Sportsmanship defines being a professional, and a handshake is just a about the bare minimum. If not that, then what?
If the US wants to be the bad boys of pool, that’s fine, plenty of great sports teams have done it. But you can’t both lose constantly and be the bad boys - that’s just a joke.
And celebrating is not poor sportsmanship. That’s false equivalence and excuse-making.