There is no "responsible disclosure". You will never get 7 billion humans to do things exactly the way you want it, so if there is a possibility of at least 1 person disclosing a zero day publicly, then you have to be prepared for it just as much as if it was everyone.
Instead of trying to control behaviour of every single human being in this world and demanding of them to do things in a certain way - which is, was and will always be impossible it is much more favourable to establish the expectation that a zero day vulnerability might be dropped every week and have businesses (vendors and clients) be prepared for it so it can be handled adequately.
Instead of trying to control behaviour of every single human being in this world and demanding of them to do things in a certain way - which is, was and will always be impossible it is much more favourable to establish the expectation that a zero day vulnerability might be dropped every week and have businesses (vendors and clients) be prepared for it so it can be handled adequately.