As a former member of the service industry, I know that in the United States, service employees rely on a combination of tips and wages for their income. I see no problem in tipping $5 or $10 per hour (i.e., $5 to $25 per hour when winning and $0 per hour when losing depending on the player’s stakes or expectation) as a reasonable kickback as part of doing business.
The question then arises that when a player wins a large amount; say $5,000, most dealers want more than just your junk red chips and silver coins. Most dealers would consider the player a tightwad unless they tip at least several black chips. Some dealers, in fact, would suggest that 10% to 15% of the player’s win is an appropriate amount to tip. Of course this is ridiculous. If tipping the average hourly toke rate (or say 2x the average hourly toke rate when winning and $0 when losing) gets the player nothing but a scorned look, it's no wonder why many players (advantage or otherwise) decide that they would rather tip nothing and not be appreciated than to tip something and still not be appreciated.
From my experience, most AP's tip what I'd call a fair amount. In fact if you as a dealer had AP's exclusively at your table all day long, your toke rate would probably be pretty close to average. I might add, there are several AP's who are notorious for not tipping, but I'd guess that there are just as many who overtip and it all averages out.
Finally, I might add, that most dealers would not recognize an Advantage Player if the AP slapped them in the face. Most AP's are not skinny white guys spreading from table min to table max drinking bottled water. We know all the casino stereotypes and use them against the house (and we are not dumb enough to believe that the dealers are on our side; they are part of the house). We have simulated your games and have sophisticated betting strategies that only high tech computer evaluation by the eye in the sky can detect and when we are backed off the dealer is usually more shocked than anyone else in the casino. If LV Bear, a notorious non-tipper, has anything wrong is his differentiation of dealers from other casino employees or the casino industry. They are all part of the same whole. When a player at your table is a water-drinking stiff in regards to tips, moving his bets up and down in dramatic fashion, the player you and your pitboss are sweating is most likely just an unskilled tightwad hunch bettor, not an advantage player. I like these players because it's their play which gives me cover to use my skills without being detected as quickly.