Why is a .22 hornet a legal rifle round for deer in one state, but if you cross the state boundary it is suddenly only a legal varmint round? Why can people use a snare in one state, but it is not recognized as a legal animal trap in another state.
But it is likely a moot point since, at the rate things are going, crossbows will be pretty much common during bow season throughout the U.S. within the next decade.