There are a ton of laws regulating wolfdogs. Depending on where you are it varies greatly. Some places you can't have them at all, you can't even transport them through certain places. Others you need a wildlife permit, and some they're considered regular dogs as long as they're under a certain %.
Here in Pa, you must have a permit from the State Game Commission, they can only be treated by a wildlife vet, they must have outdoor enclosures that are at least 6' high with some sort of reinforcement to prevent digging out. You also need permits from all the local governments, township, city, etc.

Aside from that, because the US refuses to recognize the wolfdog as a pet in any regard, it will not approve Rabies Vaccines for them. So even if the vet gives a wolfdog a rabies shot, if it ever bit anyone there is no quarantine, they must be destroyed and tested to rule out rabies. No wolfdog who's been vacinated has ever been found to have contracted rabies, but still the vaccine is not approved.

Being in wolfdog rescue, I have seen many wolfdogs come from many bad places. I've never seen a case where one needed a new home because he or she was aggressive towards people. Any aggressive behavior is usually directed at other dogs or animals.
In the wild, wolves rely on themselves. They don't need people to feed them or keep them warm. They are very intelligent, self-sufficient animals, and so naturally attaching themselves to humans and taking to training takes a lot of work and patience.
typically, they are very shy and wary of people they don't know very well, and when they can, they avoid you.
Same goes for wolfdogs running loose. It takes a really good owner/trainer to convince a wolf or high content wolfdog that coming home is in their best interest. They'd rather roam, hunt, explore, and play. So wolfdogs running loose many times stay loose, and because of their tendancy to be dog aggressive, other dogs, or anything that may resemble something to chase or hunt, is at risk.

I agree, all dogs should be leashed while in public. It's whats safest for the dog.