One thing worth mentioning here: if prices are determined by the free market they can serve as a valuable signal to increase or decrease supply in response to demand. It may well be that in the future these bus drivers could serve a more useful purpose elsewhere in society, but the signal to do that would be dampened by artificially high wages to bus drivers. Price signals are the reason our society is relatively efficient compared to, say, the Soviet Union.
In conclusion, I think OP is right, if these bus drivers don't like the compensation they're getting they should look for work somewhere else, just like the rest of us.
http://www.econlib.org/library/Enc/InformationandPrices.html