It is pretty amazing how the volunteer issue is a sore one. (I'm a volunteer by the way.)
More important, it's impossible to make broad statements about either group, however.
As for the NYC situation, every job in every area has 500 people ready to do the same work for the same pay, and that goes for EMTs, journalists, and deli workers. Heck, look at the police deal now. Recruits pull in a whopping $25,000. Is that because of the "wanker vollies?" I don't think so. It's the deal that was made between the people above.
Conversely, volunteers do provide a valuable EMS force for many communities around the US. And, to the point of paid versus volunteer, just try to float the tax increase to cover the EMS force. Communities would flip out. They'd have to bite the bullet and do so - and many are as the volunteer forces dwindle - but it won't be easy.
My point here, of course, is that in any discussion its just impossible to make broad statements about either side. If you're not happy with the pay you get in your job, change jobs or careers, but don't blame another group like volunteers. They existed before you took the gig, no?