I can see having the state acknowledge someone has attended an accredited school and passed the required course, but I can NOT see having to pay a fee every year, going to required yearly courses and whatnot just to 'maintain' a license.
It's PURE revenue generation so the State can use us like living ATMs.
Intitial licensing fees for physicians range from around $200 to about $1,200 (California of course), with the average being around $600.
http://www.fsmb.org/usmle_eliinitial.html
I’d imagine renewal fees are much lower. States are not making big bucks off these licenses, and these fees are miniscule compared to the cost of medical school and other costs of doing business.