Leaving aside for a second the fact that now tipping is basically asked everywhere (even at automated machines) - as an European I consider it an extremely stupid trend. If you're "forced" to tip, then it's not a tip anymore.
The concept of tipping, at least in Switzerland, has always been to show gratitude for an *exceptional* service. I totally understand the situation in the States, where the tip is basically the employee's wage - but this shouldn't be the case to begin with.
It shouldn't be considered rude to not tip the service was good / OK. Employees / waiters should be paid adequate wages regardless of their tips - in the end this is why the food in a restaurant is so expensive (compared to cooking at home).