I see pure talent acquisitions (no tech, no site, no brand) once a month for >$500k/head. Here the founder is a course 6 (CS) MIT grad, obviously smart and talented, able to act as an evangelist to broader communities, with a pre-built launchpad in place. There's real value to that.
If the stock component vests over some period of years, it could easily run into the millions, and still be a steal by Stripe. I'll echo another comment downstream: it's interesting to think about whether, in the spirit of the site, they will (or should) reveal the economics of the deal.
I'm going to guess they got it for a song with a job for the owner and his brother attached and the promise that they could focus on content and not selling ads.
Also the lawn care point wasn't an anecdote it was an example of a generally predictable and steady income stream business vs a blog like this which is neither.
They might have paid some premium but they aren't paying 150x when the going rate is <2x AND throw in a job for the brother.
You need to look at it as the total value this will provide Stripe. It's a community of people who will buy their service. It's good will too.
Community outreach is a good thing (tm) but I see now way any sane/experienced business person would pay a million dollars for this.