I think over 100 years of people pumping their gas without issues speaks for itself. If there was an issue with the practice, gas stations would pump your gas because the insurance required to do otherwise would be cost prohibitive. That’s the wonderful thing about having free market decisions. If you don’t like pumping gas, you can spend a little more.
I don't think that there is anything wrong with requiring someone to have to actually pump their own gas. It is not as though doing such a thing is a very difficult task that few people can manage to do. We could all use a bit more exercise these days.
By having workers pump gas, people do not realize but it is important to the economy as it proves people with jobs. With the shortage of jobs already high, why destroy one of the jobs people already have limiting the job market even further? Also, those who pump gas are more aware of the needed around the machines rather than let some wild teenage kids attempt and wield such a machine that can injure themselves and others, which would spell lawsuits.
If there is a service that makes some people's lives easier and creates jobs, we shouldn't be so quick to dismiss it. Sure, pumping your own gas makes you more responsible and aware of the costs, but having someone else do it will keep you warm and lessen the number of pump mishaps that comes from people unfocused at the task at hand.
If people want to pump their own gas, let them. If not, let them pay someone to do it for them.