Tipping is always a sensitive issue. Camp tipping is very important especially showing and teaching kids hakaros hatov. Not everyone pays the same camp fees depending on the family income and scholarship, etc. Many kids are children of Rebbeim, etc. So tipping is separate from camp fees and parents should not forget about the waiters or the Lifeguards which are usually forgotten. And that goes especially for day camps. Everyone forgets about the Lifeguards who do a very important job for all of us and it is not easy considering how many kids are at a pool or lake at one time.
As far as Pesach tipping is concerned….people feel that they are paying way too much for Pesach as it is and yet they still go. It is not fair that caterers and hotels hire wait staff and don’t pay them. THEY know good and well that inzerer yiddin don’t feel like shelling out much at the end of the chag and they should either collect it upfront in taxes and fees, or include it in the price of Pesach and “PAY” the staff themselves. They probably do this so they don’t have to withhold taxes and pay all sorts of insurance, workers comp, social security and other taxes for them. But that is totally unfair to the staff and a chilul Hashem.
As far as wait staff in a restaurant, it goes both ways, the restaurants do not pay the wait staff and so if they include it in the bill as a 18 percent gratuity it makes it easier, but if the wait staff does not do a good job you should be able to remove it and let the owner or manager know why. YOU shouldn’t be forced to pay it if it isn’t warranted. And there are very unscrupulous owners who don’t give the staff the 18 percent collected anyway. Of course if you received excellent service you can add to the tip because that is all they get.