I agree that the tipping culture is out of control with it now happening at places like Subway and whatnot, but when it comes to servers and bartenders, I think it is important to remember that their hourly rate is way below the minimum wage because they are tipped employees. For most of my tenure as a bartender, my weekly check was basically nothing because everything I made was from tips.
Now, there is a BBQ place I go to here in STL and I tip them like $5 every time, but that is because I go there enough to where most recognize me and they will usually ring me for a kid's meal (so basically my bill which should have been around $15 is like $7), so even with tipping them, I am still saving money vs if they rang me up normal and I tipped them nothing. Plus, if you are a regular anywhere, tips ensure little things like that. If you are a good tipper and the bar is packed, you are likely to be gotten too quickly. We had a guy way back who would come in once a week, drink one beer, and leave. Never tipped a cent. Not a big deal, because enough others would tip, but if he came in when the bar was busy, he was gonna wait before we got to him, even if that meant getting to others first who got to the bar after him. Just the way it works.