The attitude exists because people are willing to support it. If you knew there were legions of taxi drivers willing to give you a ride for free if it meant you’d use them again in the future and hopefully pay them if they did a good job, you can bet you’d see a whole lot of people exclusively seeking out free taxis.
On the subject of plumbing though, I feel like people who use that analogy don’t know how common it is for people to try to rip off plumbers. Because if anything it’s proof that people will gladly accept services with the intent to worm out of paying for it later. My friend was saying his dad had something written into his contract saying he could put a lien on your house if you failed to pay him within x-number of days because it was so common for people to give him the cold shoulder when he tried to collect.
