That's not necessarily the case. A bar that has a bouncer all the time? It might be that they get a shitty crowd, but a lot of times it's just that the bar is too busy for the bartender to remember which patrons they've checked IDs for. The simpler solution is to have someone stand at the door to check IDs so that every one inside has been checked.

I worked at a bar that only had a guy outside on Thursday, Friday and Saturday after 9. The rest of the time it was slow enough that the bartender could just check IDs before the customer was served.

I think the greatest thing about this is the choice. If you don't like this practice, vote with your wallet. If you do, then the same rules apply. I think the biggest issue a lot of people may have is the possibility that the choice aspect is taken away.

Right....

I mean I might want to go to a bar that's full of KKK members, because they serve nice beer. I have 2 choices go there for the beer, and perhaps inadvertently support the KKK, or the bars stance on that. Or I could not drink there. That's my choice, I'm not sure I could go to the anti KKK league rally and complain that I want to drink at that bar.