In the US many service staff are only paid a wage to cover their taxes and live off their tipping income. At most restaurants in the US, if you tip your server less than 10% they actually lose money by serving you as taxes and tip-sharing is generally done as a percentage of their sales and not actual tip amounts.

Loving or hating the system is totally irrelevant, it's the way it is.

Tipping vexes many Americans when traveling overseas because it's often difficult, especially in place like the Maldives, to know if the staff is earning a wage that's suitable for them to make a living on prior to gratuity.