zombies, shills and bots. Is there a way to weed them out?

... it's definitely the former

That is an ungodly like/dislike ratio which isn't even possible naturally IMO. Even if your article was about how you like to drink piss for the vitamins in there it would have a more favorable ratio.

To answer your question though, it would be on the site to weed them out which comes down to security measures.

A couple security measures that could help with that:

1. Strict 1 vote per 1 IP address
2. Not accepting comments/votes from VPN's or other proxy IPs.

At the end of the day, the majority of people who spam in any capacity whether its votes, comments, creating fake profiles.... rely on cheap proxies to get the job done. Or loopholes like being able to use the same IP over and over again on the same article vote.

Is it possible that 600 people misinterpreted what you were trying to say?

Depends what you wrote and on what site. I can easily believe even on reddit 2021 (as opposed to when it was openly a "jailbait" site) you'd be downvoted to oblivion for suggesting some form of censorship. Plus, yes there are an ungodly amount of people into that kind of shit.

The thing to look at is number of comments, if any. If your article wasn't controversial enough to generate more (abusive) comments than usual then the downvotes are probably fake.

Thanks! I can't help the other site but I'm going to do this on our sites.
It's possible because the Internet is filled with mostly stupid people.
(Just look at the politics section)

I agree that Reddit is a pathetic joke but it wasn't Reddit.
Also, there wasn't a single comment written.