Exactly. People are just inviting you to their clubs randomly to get members. You can destactivate club invites somewhere in the settings I think.
Why do I get so many club invitations?

You can turn invitations off in settings if you don’t want them. Be pleased that clubs think you are attractive to have as a member.

I'm not sure that I want to turn off club invitations, I might miss something that is actually interesting. Actually, this thread is not so much about finding a solution because it's not a big deal. It's more about understanding why this happens.
What's the point of sending thousands of invitations to random people? I mean, even if you manage to get several hundred people in your club, you'll end up managing a club where you know nothing about the other members and they have nothing in common with each other. What's so nice about that?
Every week I get about 2-3 invitations to join random clubs I've never heard of before. I find this mildly annoying. It would be nice if those invitations had anything to do with me or my interests, something like "since you're interested in the Ponziani we'd like to invite you to our Ponziani lovers club". But what I receive are just generic invitation messages. I have barely written in the forums since I joined, so I wonder why they invite me. I wonder if it has to do with my Elo, which is around 1500 in daily, which maybe makes me more attractive to club admins. Or maybe there are just lots of club admins who use all their invitation slots to spam every single forum poster they see?