Because the state licenses the hunter, not the implement.
I'm sure if teh DPRM could come up wtih a way of making raptors buy licenses and stamps, they would.
Note to the person that wanted to go along with the falconer -assisting (e.g. beating the brush piles with a stick) in the hunt is considered to be "hunting" per the Mass regs. You "need" a license. I put "need" in quotes, because I asked an EPO about it, and he said, yes, you need a license, but we generally don't bother falconers, because they're all crazy."
As for hunting larger game, Go Roc or Go Home:
en.wikipedia.org