thanks for posting that, singingpixie -- I was just about to go on and say something like that myself!
It seems doubtful to me that any of the rest of you have ever worked in counter service, or been in a situation where you got to "choose" (the term that Kandeebunny used) between a job working behind a counter at a coffeehouse and a job at
Walmart, or, for that matter, ever tried to support yourself (and perhaps pay for tuition or perhaps support a child) on minimum wage.
The point of a tip jar is that it is completely optional -- no customer is required to tip, and no customer will be treated badly because he/she doesn't tip. (So for those of you who are upset by tip jars, just go ahead and "choose" not to tip when you buy your coffee/ice cream/etc at an establishment at which servers "choose" to work.)
Tips are often given for especially excellent service; the existence of tip jars tends to enhance the overall quality of service, since servers never know whether or not they will be tipped. Tips increase a server's wage, and therefore increase their job satisfaction and desire to please their customers. An individual customer thereofre (whether he/she tips or not) *benefits* from the existence of a tip jar.