I think the problem a lot of people have is transparency. First, it's not clear what rule the posts are breaking. You also only warned one individual, in a very vague way that could even be construed as a joke, instead of making a pinned post or elaborating in any way, shape or form. I've had a user message me that they were banned for making a similar post to this one, with no warning, and no follow up explanation, and I imagine there's a few more as well.
Secondly, and this is coming from experience in other subreddits: when a dev is active in a subreddit, it can breed resentment from the user base. Typically because either A) the common complaints made by that subs users are ignored or B) the uncommon complaints/vocal minority are taken seriously. I'd say GSG is moreso in column A. I'm not saying either thing is necessarily bad, but when the dev team is not listening to complaints, not giving clear and concise reasons why they aren't, and actively moderating the sub all the meanwhile (and removing dissenting users in the process), it can breed resentment.
Escape from Tarkov suffered from case B where the game design lead was very active, but started to listen to a vocal minority (streamers), and made active changes to the game based on their criticisms, which clashed with what the majority of players wanted. This bred resentment on the sub, with lots of users making lots of posts complaining about the changes. A rule was eventually made containing the complaints to the games official forums. A similar rule was made for accusing cheaters with video evidence, and even just submitting bugs in general, because of how overloaded the sub became.
If the dev team were moderators, those rule changes would've been received MUCH more poorly than they were. Because it would've seemed like they were just silencing their critics. So I stand by my opinion - Devs should never be moderators on their games' subreddits. It just makes even GOOD, VALID decisions seem tainted by malice or contempt. Like how the branches of government are separated.