Why do stars choose such profession which spreads hepatitis, HPV cancer, STDs, giardiasis, amoebiasis etc.?

They have 99.99% chance of getting infected by fatal diseases in long career. They obviously get it if not in first then in second if not then in third.......then in thousandth performance in career. They are forced to do vomit inducing disgusting acts and even eat faeces or drink urine or eat fluids and farts semens yuk!! If they know this, why do they enter such profession? What options do they have if they leave their profession? What is their life expectancy and life after career and what is shelf life of a star?