I've already answered that.
Is that based on knowledge, experience, or just prejudice? It is common in Europe that tips in an establishment are collected together and divided amongst all the workers.
Exactly. Tax-free, unregulated payments with cash-in-hand that is not recorded anywhere - when it is used instead of normal payments, it is known as the "black market".
Getting /properly/ paid by your employer for doing your job is all the economic incentive people need. Getting thanked, meaning customers say "thank you", or talk to you - that is personal thanks. In exceptional circumstances, leaving a tip for outstanding service is personal thanks.
Having customers judge you and determine whether they will give you enough charity to let you pay your rent /and/ buy food this week, because your pay is not sufficient - that's not thanks or incentive. That's desperation.
That is not how socialism works. Socialism is about society helping individuals.
Is that based on knowledge, experience, or just prejudice?