Milwaukee fans gave Ryan Braun a standing ovation for his first at-bat since serving a 65-game suspension for his role in the Biogenesis scandal. This shouldn't be a surprise—Crowd Cheers its Team's Best Player—but some folks seem to have forgotten how this thing goes.
Idiots? Nah, just regular fans, who cheer their team, and who will cheer anyone who can help their team win, and come to the ballpark not to have ethical debates, but to root for the the Brewers. That's sort of the entire point of being a fan. There are MLB teams that employ drunks and women-beaters and rapists, and the whole enterprise would fall apart pretty quickly if fandom had a character clause.
Fans have cheered players who failed PED tests. They've cheered players who failed PED tests and lied about it. They've cheered players who failed PED tests and lied about it and were generally dicks to everyone. Not sure who was expecting "smearing a sample collector" to be the behavior that finally put a player into the realm of the uncheerable. Really, the only thing Ryan Braun could do to get booed in Milwaukee is to stop being good at baseball—or to stop being a Brewer.