Internet forums, and the "fit" of any given person, are kinda like those "venn diagrams", where hopefully you fit in that little triangle in the middle of all three circles - except that the circles move around. So what might have been a fit when you began, or even you fit, but were only in two of the circles, can change. And that's okay! It's unfortunate that any contributor would choose to leave, particularly a valued one, but people's interests and opinions can vary over time (one circle), the circumstances of our world can change (another circle) and the theme of the forums, and moderation can change (the third circle). Occasionally the result is that you're not in two of the circles any more. The best thing is to realize it, and either move with a circle, or step back from two of them, neither is wrong - it's a personal thing. Honestly, there are topics on this forum I would not even open, they potentially offend me. But that's my problem, not that of the forum, or members. Happily, I'm here to talk about tractors, and that's going well, so the peripheral topics are unimportant to me anyway - I wouldn't touch them on the aviation forums either!
I'm a moderator on two aviation forums, each with surprisingly different guidance from administration about what's acceptable, and what's not. But the basic fact is that the forums are someone's "place" and we are guests. Hopefully the member who has announced their departure has inspired members with a sense of tractor community, and that will carry on as a positive! We won't celebrate a loss of a member, but we can still celebrate their contribution and value!