I opened my HN client and saw multiple posts at the top of the home page about this datastar thing, with comments like yours either very aggressively defending it or praising it as the best thing since bread.

Did you forget one of those "full disclosure" thingies at the top of your comment?

In any case, I didn't see anything interesting about it, even less so after reading OP's useful comment on the pricing, but even if I did I would never intentionally use or give money to a company that does astroturfing campaigns.