@Winged Your last line is perfect. Up until this year (and still sometimes when I help my family restaurant out) I have lived on the 2.13 bullshit. Many days I went w/o making min. wage b/c my restaurant was so low. Now my boyfriend is a bartender and there are days where he doesn't make enough money to get the gas to get there.
Every table counts ppl. Don't eat out if you can't tip. Even lousy service my boyfriend and I tip (granted if it's lousy service it's like 10% instead of the normal 15-20% we usually give). I can count on one hand the number of times I've NOT left a tip when I went out to a restaurant.
If your server is busy and you don't get your ass wiped every minute you're there, cut them a break; they're busy, not ignoring you. However, if they're ignoring you and they're slow, that's on them. If you don't tip then, I wouldn't blame you. I hate it when someone is slow and clearly only has the one table (aka me) and my drink has been empty for the past 20 min.
If they look tired, they're probably tired. I know of so many ppl who supported their family on 2.13 an hour plus tips. On the days they're not busy... they're shit out of luck. Bills aren't getting paid and they'll be lucky to feed their kids. So fucking tip. Srsly. If you're lucky enough to have a good paying job... TIP.