Okay, I'll bite.
You know why this frosts my cookie? Because there are people out there who NEED tips. Who LIVE ON TIPS. Waiters who are paid $2.13/hr (not kidding, look it up) who are forced to "tip out" 3% of their sales to bussers and bartenders. So, literally, they get to pay for the privilege of waiting on patrons who don't tip them. And this is not at all uncommon. Or pizza delivery drivers who pay for their own cars, their own gas, their own insurance, their own maintenance out of minimum wage.
And now the Starbucks baristas have their little jars out. Sure- they get paid an hourly that isn't artificially lowered to pass on the labor cost to the consumers, but tips are nice, right? And maybe if they start taking in enough, Starbucks can lower wages!
And now there's you, who just loaded an entertainment center into someone's SUV. Standing there with a smile, your hand not quite held out, but an expectant look on your face.
And people start railing against "tipping culture" and "why do I have to tip EVERYONE now?" and "I had to tip at TARGET!" or "Fuck it, I'm not tipping anymore!" And you know who gets really, really screwed? The person making $2.13/hr and in debt to the house 3% every night. Not you.
Yeah it's a cultural problem, and maybe paying adults less than three dollars an hour to do a job is horrible, but that doesn't excuse you from blatantly ignoring your employers policies and taking part in the problem at the same time. You make us all look bad.