Is there some reason we can't do both; chew gum and walk at the same time?
More often than not, animal abusers turn into those who murder/abuse children and the elderly. No sense of guilt. No conscious to keep them from doing it. No empathy.
If we identify them early when they are abusing animals; maybe we can prevent some of the crimes against people later on. That's the theory anyway. There may not be a way to fix people who can't feel guilt or empathy so what do we do with them? Nothing is stopping them from being the next mass murderer or whatever. If we can identify, test, and treat those who can be fixed and figure out what to do with those who can't; maybe we have made the world a little better.
I dunno; it's too big for just any one person or group of people to figure out. I do know that putting the head in the sand and ignoring the problem isn't working.
No one wants to see any loss of rights or privacy but we can't solve problems by ignoring them. I know people like that and it never works out well for them. It always catches up.