I do agree that it's crappy with the whole knocked wage to account for tips. What makes it worse is if you work at a place that pools the tips then divides them up. The has been something that has always irritated me.
I am sorry if I come off as an ass, but I see a huge problem with tipping for crap service. It's a reward for not trying. Most people are only willing to do the barest minimum and if they get rewarded for doing a shit job it will just reinforce that they can phone it in and get rewarded. Would you call the manager at the grocery store and say how great the bagger was if he/she smashed the eggs with a watermelon? It's the same thing.
I just couldn't fathom tipping the server that brought us incorrect drinks, said that she would get new ones, didn't, took our order and promised new drinks, then went on lunch and didn't tell her cover about us or got the drinks. After about 20 minutes we got a person that got a manager and turns out she never even put the order in. She then was nasty because she got reprimanded for basically doing a crap job.
Yes, it sucks that when they don't get tipped their pay can be really shitty. It's the same thing for commissioned sales people. I got minimum wage (granted it's much more than $2.13, but still not a lot) until I beat that with commissions. I worked that way for years, and I busted my ass to give the best possible service so I would make the most money. I got myself regulars that way. It's the people that provide the services responsibility to the customer to get tipped, not the other way around. I will tip 40-50% if I get absolutely stellar service, but will happily leave nothing if it sucks in hopes that the person realizes they could do something to change it.
I know this is a matter of your opinion versus mine and while they are both valid, I had to disagree.
End rant.