First, can you provide references to your assertion that Tailscale is being mentioned "every 3 days"? Doing a search for "Tailscale" with a "past month" limit is showing 2 front-page hits: "Tailscale SSH" and "Tailscale ate my network". There are two other submissions that didn't make the front page, and one Tailscale alternative that also didn't make the front page.
My personal opinion is that missing either one of those posts through a "once a month" rule would be a negative to me. I personally read both and interacted with both and got value from them.
Deno and fly.io are also things that seem to have been mentioned a lot lately and while I'm not in the "market" for them like I am for Tailscale, I still find it useful to see those mentions.
Much of what I get from HN, like going to Python conferences, is just hearing the "word on the street". Artificially muting that word on the street because something similar has been mentioned within the last month, is a disservice.
Finally, your point about "Say I have a tailscale alternative, how do I overcome the Tailscale inertia?"... You do cool stuff. Tailscale SSH is something they recently built and is very cool. However, the first mention can ride on the coattails, much like one of those tailscale references I mentioned above: "netbird is a tailscale alterantive". But it just didn't generate enough interest.
If you can show legitimate vote fraud or the like that is leading to Tailscale showing up unreasonably frequently (again, it seems your perception is skewed, because TS has only been frontpage twice this month), then that's one thing. But muting what other people seem to be legitimately finding interesting is totally unreasonable.