A couple of different reasons, I think:
1) lots of folks WANT to carry. they just dont want to be restricted to CC as the means of doing so. Hence, a lot of folks just dont bother,if they are only going to be CC.
With the announcement of this bill, and almost everyone being led to believe it was intended for Open Carry, once the word got out people started applying for their permits in anticipation..hmm est. 180,000+ disgruntled voters?
2) crime in a lot of areas -despite what the sheriff's offices are saying- is getting more violent-blame the economy or whatever u need to. folks are feeling a need to arm up.