It is possible to respect their efforts, but refuse to sign up for things on principle.
And, if the account is "free", then why did you need to give them an email in the first place? If they aren't getting money from you, then needing a login that would require an email address is sketchy as hell on the surface, and there's no explanation given.
Yeah, blocking the site in its entirety is kinda weird, seems like extra effort for no benefit at all when you can just not use the site. But objecting to what is a pointless "account" unless they're monetizing the information makes plenty of sense. Worker owned is not a guarantee of good behavior. It certainly helps, and it's the superior business model imo, but it isn't inherently going to mean they aren't doing dumb shit.