A curious approach, but I like it!
Wonder if this means just publishing vulnerablities without contact with curl team would be responsible (you have no other path to tell vulnerable users)
It would certainly be irresponsible.
The responsible thing would have been to simply wait another month, considering you've been warned about the delay.
Given that most of those users will not be capable of patching it directly, no, that seems like it would be irresponsible.
Just publish early due to a documented lack of cooperation. They don’t have to answer, but you dont have to wait.
Naturally some people find that this offensive since this puts a price to that “bliss”.
I think very few people would consider that to be responsible disclosure. The common practice is to allow 90 days as a minimum.