Project Zero (and infosec professionals, at least all of the ones I've ever worked with) would tell you that this was the most irresponsible way to handle the issue, short of not saying anything and selling knowledge of the exploit to someone other than the vendor who could fix it. Publicizing something like this in this way is something people do because they want publicity for themselves. It is not something someone does if their biggest concern is for the users who might be affected by it. It is something someone would do if they didn't care about the users, and just wanted public credit for pointing it out.
