I would, personally. Not on the level of service, but on the way the worker should be compensated. I hate it when employees are pitted against each other at a workplace, like how they often do with sales people. I think this is exploiting them, and I don't like the idea of that, no matter what results it produces.

And you'd be wrong about tips. They are at quite a lot of places, in fact, I find that it's rarer when a system or culture explicitly does away with them. In Japan for example, people can even get upset and give back the tipped amount. And at many places, it's not called a tip, but it's rather a bribe, but frankly, I think they have a lot in common.