Latin people take their dancing seriously. Whereas the typical American, if he can dance at all, will only know hip-hop MTV style grinding, Latin people have a wider repertoire of moves. Salsa. Tango. 1-2 step (not quite sure what that is). And a million other variations.
There are also set expectations for how men are to ask women to dance whereas in the States it's more of a free for all.
At the one club/bar I went to in Montevideo, grinding was eschewed in favor of circle dancing, solo dancing, or other local variations.