A true professional can leave his job, take his skills and experience and apply it somewhere else without skipping a beat, and even get an immediate raise by switching jobs.
This is not true in all cases, the grass is not greener. I am on the other side and the above statement is riddled with ignorance.
In regard to tips, I have constantly heard pilots compare this profession to being a Doctor or a lawyer. Do you see a tip jar outside the OR? If you want to be paid like a Dr. or a Lawyer, quit and become one. Pilots are labor, you can only get paid what you can negotiate. Don't throw away your dignity for a lousy tip jar.
(I do agree in most cases that pilot pay needs to be improved)