My vision for this place is not a place to debate socially important topics that have a connection to science and nature. It is an instance to identify plants and mushrooms, and discuss recent papers.

I'm 100% with you. But, there's no completely "depoliticizing" those conversations even if you wanted to, even if your community was fully on board with that. More importantly @fossilesque is still correct in their assertion that it is only a matter of time before a community devoted to science and nature is a major target for bad actors - doubly so because your instance isn't limited to just your interests. If you want something just for your topics, you should moderate accordingly (as much as I would be heartbroken, given the fact that something is growing here).

My current perspective is that I should have already had a policy in place, to make it clear what I want.

Exactly. Narrowing this focus down - as much as I'm against it personally and would encourage you to take a real look at the community that's getting a start here before doing so - might be the right call for you as admin.

I actually do want to hear this rant, because I feel like this might hit the nail on the head on how I feel

Background: I'm a IT/Cyber guy turned social scientist. The short version of the rant is that the philosophies and conceptual frameworks of engineering are not suited for understanding or even working with social groups. Imagine a social scientist with no other training turning to you and saying "I'm going to build a new utopian community, and I'm going to build a really tall sky platform where we'll all meet and live! No, no, I can build it myself. I mean I live in an apartment building that's tall, I get it, it's not that hard. Can I borrow your truck?" There are actual reasons that people spend decades studying our social world, and notably we are still struggling to really get a handle on how communities build, grow, and die online. The ones that are closest (for example, the widely circulated article on enshittification from Doctorow) tend to be people that understand that technology is inherently political and social, and that both technical and social forms of expertise are necessary to intentionally build communities. Beyond all of this is an inherent positivism to engineering - the idea that you can simply brush aside bias and context to get to "the truth" or "the right answer" of anything. While this approach is deeply flawed more generally, it works pretty great (by which I mean it creates measurably effective solutions for the problems as defined), especially for things that are technologies that don't deal much with human beings, or worse, social groups.

There's more to say - specifically tying things down to this example with Lemmy - but it's the weekend and I'm kid wrangling.

I want to have a space for my hobbies not argue with people.

There is no community without challenge. No community without tension. Healthy communities grow through and with the challenges, it's the churn of novelty and acceptance that makes the community.