Wow you weren’t kidding. I went to the payment page at https://developer.mozilla.org/en-US/payments/ and it says they only have 44 monthly supporters. I’m going to donate now though, thanks for the heads up on this.
Edit: Unfortunately It appears that you can’t donate to MDN anymore because the “manage payments” page 404s.
That was a limited time experiment, which got shut down after it didn't prove very successful. But from that, it's probably a fair guess that it would not perform well if rolled out again today. There are a few very vocal people who want to support MDN, and that's great, but that's probably not true for the bigger audience. :(
I was about to comment this. Its a damn shame they didnt leave it active and lightly tugged people on MDN about it... Hell even a few social media esque campaigns about it to raise awareness would of not hurt.