Why don't more people thank the bus driver....

Lots of people on buses round here (metropolitan London) do. Personally I find it slightly odd, because the driver is only doing the job for which he or she is paid for, and sometimes does it not very well or slightly grumpily (and in some cases will recently have been on strike!) It’s certainly much more common here than it used to be. Of course if the driver has done something helpful or beyond the call of duty, like waiting at a stop while someone runs or limps to catch the bus, then it’s important to thank them, and almost everyone does.