The majority of Americans work in the service industry, change the laws.
Some think the rules should be changes, some don't, but it is what it is. As with many things, one should acquaint him/herself with rules and customs in the country one is traveling to.
If, like in Poland, the servers are graduate of some gastronomical school (once, in Poland, I was sternly lectured on the fine points of a balanced meal by my waitress) and getting a "sufficient" hourly wage, you rightly might get the 'don't care' attitude.
In US, since the servers' livelyhood depends on not getting stiffed, you'll get all this hi-voltage "Hi, my name is Steve and I will be your server" bull****. Here, the rule is that if want to sit your a$$ down and be "served", add the 15% to the prices as you're ordering. If you don't like the service, complain to the owner, don't come back, but don't be a cheap d!ck. Here, if the service stinks, my bet is that it's not the servers fault.
As far as Canadians, I have gone as far as friendly inquiry- "where are you from?" and if your country is on the "list", then you cannot be trusted with following the local standards, and the 15% gratuity is automatically added to your bill.
So read your check carefully.