20 Percent? REALLY?

I just discovered that not only supposed to tip my server 20 percent, but my hair dresser and dog groomer, too?!? (I knew about the server part..just not the other two) What? That's craziness? No offense to all you dog groomers and hair dressers out there...but that seems like pure ridiculousness to me! It just doesn't seem fair that someone who fixes my hair should make as MUCH an hour if not MORE per hour as I do! I'm out there saving lives! I don't get tips?!? I pick up poo..I get it on my face...if that doesn't deserve a tip...I don't know what does!I mean seriously, a $20 tip just to get my hair highlighted seems very unfair. I'm boycotting.