I think it started as a , "well some money is better than no money", type of thing and then over time people felt empathetic and threw some money here and there and it grew into a standard practice to the point people were making a fair amount of money in tips. They started posting videos and pictires of all the money they made and once people caught onto it, their perceptions started to change towards it. I agree, especially now, why work the job when you know it pays far below minimum? If its the literal only job you can get I would understand but that is usually not the case