Sorry, this is definitely not the case. Many times the worker is doing exactly what is needed and nothing more (eg: pour a beer in a glass, handing me a pizza). Why would I be considered an asshole if I didn't tip? That is ridiculous.
As other people have said, tipping in the US has really become obnoxious. I definitely tip while seated for a meal, but asking for a tip to hand me a cup of coffee, pour a beer, etc only makes the system worse.