Wow, I couldn't disagree with you more, Cris.
First of all, a waiter/waitress is doing a hell of a lot more than "pick up a plate of food and walk 20m." Have you ever waited tables or known someone who does? Do you know how much they get paid?
I think you're making the opposite point than you intend. Tip culture causes underpaid waitstaff, not the other way round.
The minimum-wage law in the UK, BTW, has no exception for tip-heavy roles. (Nor, according to Wikipedia, does Oregon's.) On the other hand, it
is legal in the UK for establishments to operate a tip pool or suchlike, so your money doesn't necessarily all go to the one individual you expect. This is at least as bonkers IMO.
Peter