Getting back to the bow hunting question...
I dont know the exact reasons for the law here. I can only guess that someone mixed a cocktail involving poaching, lack of licensing, pictures of animals shot by vandals with target points, and possibly some gun hunters who felt a vested interest in keeping archers out of the woods, and fed it to the law makers. All that would have been needed would have been some photos of animals crawling around with targets arrows stuck in them and a news story about how this was being allowed by the law and the general public would demand a ban. If there werent all that many people hunting with bows to begin with it would be a walk over. That is just my thought.
I did hear a rumour that someone published a picture of a duck with a target arrow in it. The rumour said that the picture had actually been taken in Central Park NYC, but that the reporter hadn't bothered to cloud the cruelty issue with such facts. Have no idea if it is true, but it seems exactly the sort of thing that could have triggered a knee jerk law change.
The debate as to whether shooting an animal with a broad head is more cruel than shooting the same animal with a rifle has been going on for some time in the US. One could argue that unless you get a human guinea pig to experience both, you will never know for sure! Last time I paid it any attention the general opinion seemed to be that a well placed shot from a bow was just as quickly lethal as a well placed rifle bullet on deer. The important part is the placement, bows being harder to use and more unforgiving of error. I would go so far as to say that in my opinion the majority of archers I have seen shooting Field Archery are not good enough to go hunting humanely. I include myself in that. The advice given in the US to people who are planning to bow-hunt is to shoot something like 40 arrows a day for 2 months before hunting season starts. That is, shoot as they mean to hunt, not just at a clear target at known range.