I've tattooed plenty of cops, no big deal. Lots of cops have tattoos. To think that most or all tattooers hate them would be similar to saying all cops are dicks. I know it's not the case, I've met plenty of good decent people in an underappreciated public service with a through-the-roof danger rate. I appreciate the people that truly believe in their job. There are plenty of people that don't entirely trust or feel comfortable around police, whether it be deserved or not, but I know that's not new to you and it encompasses lots of people besides tattooers.
Are there some asshole tattooers out there? Yes. Are there some cops out there that are bullies and abuse their power? Yes. We're all just people, and if you're a dick then that's just who you are no matter what field of work you are in.
If you are not comfortable with your artists, then don't get tattooed there. I wouldn't want to pay someone that hates me either.