all gambits are juuuuust fine. some are more ok than others.
sometimes a gambit can even be the best option in the position (an example, e4 c5 f4 d5 ed Nf6 is considered quite reliable for Black)
except the latvian gambit is awful. don't play that one. the rest are ok!
In the example of the Latvian Gambit it seems clear the the player of White did not know theory. Correct is 4. Nc4! Leonhards variation. This line, [I think] gives White the advantage in all variations. as in D.Taylor K. Reinhart, internet exhibition game 2004.
But it is true if White does not know the good lines he can fall into a bad game.