Eh, are they paying them? If so, the solution is exponentiating fines. The city needs revenue. And it’s not like San Francisco’s human drivers are following any of these rules closely.
This comes out to roughly 1 parking ticket per vehicle every 2 months.
Not something to do nothing about, but also not especially surprising for a taxi service in SF, imho. It would be interesting to see the numbers for Uber/Lyft/taxi drivers.