No service = automatic tip?

Here I am in Orlando for the week. The trade show this year is at a spangly new hotel called the Rosen Shingle Creek. It's all very Las Vegas. I think they're trying to pull off a pirate ship theme. Either that or it's unbelievably tacky decor. The rooms all have high ceilings, light switches that you can't find in the dark, a bathroom sink which is so high off the ground it even makes me (1m 87cm tall) feel like I'm a kid at a washbasin, and the walls are all painted this interesting shade of cream which makes your eyes hurt to look at it in the light, and in the shadow looks like poo smeared on the wall. There's genuine authentic fake dark cherry wood furniture that looks like it came from the 1800's (except it's made of fibreboard) and a hyper revolting carpet that even the Little America would be proud of.
Anyway, I went for breakfast this morning to find my pet hate - a breakfast buffet (where Americans fill their plates with 3000 calories-worth of food, then nibble a bit of bacon and half a pancake and throw the rest away). I had my usual - cereal and toast, and was pleased to see it actually cost less than the buffet because perversely it's normally the other way around. Being a buffet, of course, it's self-service, so I was intrigued to see an 18% gratuity included on the bill. No problem, I thought, I'll just remove it at the till. And that's where it all went wrong. I tried to explain to the girl that putting a gratuity on the bill for a self-service buffet was bollocks but she wouldn't remove it. In the end she had to call the restaurant manager who explained that I was paying for the congeniality of the staff. I explained to him that a waiter throwing a menu at me, bringing a single glass of water to the table and insisting on calling me 'bud' wasn't worth a $2 tip. Perhaps if he'd got the cereal for me, or in any way given me some sort of service, it would have been different. I lost the argument of course and on top of that, there's a line on the bill for "additional tip", which the manager dutifully explained to me was where I really should be putting the tip. In disbelief, I explained to him again that at a self service buffet, there is no tip, and that if anything I was going to put a negative $2 in the "additional tip" line and take it off the bill. If they're going to automatically include something on the bill, don't have the balls to call it a gratuity. Just increase the price of the breakfast and be done with it.

Here's an additional tip : Don't automatically put a gratuity on the bill for a self-service buffet!
Idiots.