I remember when snagging for salmon was legal here in Michigan.
I have no way to prove that bowfishing is safer, but I can tell you it is.
I wonder what safety issues they are concerned with? How safe are huge, weighted hooks lobbed into the water, and yanked back repeatedly?
Back when snagging WAS legal, it was not uncommon to stand shoulder to shoulder, and have hooks land beside, in front, or even BEHIND you, from across the river.
Here in Michigan snagging was banned for a number of reasons, INCLUDING safety. Bowfishing thrives.
Maybe you could contact the Michigan DNR. There are several big bowfishing tournaments here in Michigan, with tons of participants. I have never heard of any injuries. (michigan.gov/dnr)