Moderators can quit moderating if they don't like Reddit's policies, but sabotaging a subreddit like this is wrong. I don't want off-topic porn in a subreddit I am reading.
How do you propose that the community protest the recent changes? If mods lock the sub then admins will open them back up, and select new moderators who will tow the reddit line. Filling subreddits with porn is their way around this, that reddit wants to put an end to, but then reddit wins again. Hurt, specifically branding and financial damage is the only thing that can elicit meaningful changes because there exist the likes of those who don’t care about this whole saga. The pissants that will gladly walk past a picket line. The point is that you shouldn’t want off-topic porn in a subreddit you’re reading but you should recognize that if you continue to interact with reddit in the ways you normally would then everyone is deprived of meaningful recourse. Though it is Reddit’s site, and they can do what they want.
You can look through my comments on this if you care, but I've been for the protests. What I've thought is that everyone needs each other. Reddit needs the mods. Reddit needs the users. The users need the mods, and, obviously Reddit for the platform. Reddit needs the mods for their free services, and, obviously the users.
Protesting because Reddit is making life hard for mods and users is one thing. But doing so in a way that is harmful to users means this little social compact isn't upheld.
"Start your own sub" or "just be a mod, bro" would be fine if the mods "owned" the subreddits, but they don't and they shouldn't feel like they do. They are entrusted with it and users generate the content.
There are problem mods. They can break their own rules with no recourse. Complaining about a mod harassing you gets you a "too bad" email from Reddit because they rely on the mods.
Users are the only ones who have no other recourse than voting with their feet. If a user likes r/thing and then r/thing is filled with porn so that the user can't even use it anymore half the waking day, then they will leave and I don't think Reddit is wrong to do something about this.
If you aren’t willing to leave and the userbase doesn’t significantly decrease it doesn’t matter.
Platform is important but it’s still secondary to number of users and communities in the world of social media.