Earlier quoted context omitted.
I'm not sure if I would ever fully support this kind of disclosure, but maybe we should consider that both this person and Stefan Esser (DYLD_PRINT_TO_FILE) concurrently released fixes/mitigations, meaning vigilant users are secure faster than they would be if it was kept secret until Apple patched it.
Are you talking about his comment about -no_shared_cr3, which causes a noticable performance degradation, and how he will be releasing a kext soon - neither of which is mentioned in the github readme, but buried in HN comments? A small portion of users might be considered vigilant, but they're not psychic. The largest target for local privesc are the people who get hit by different kinds of malware, usually as a payl…
There are people in this thread more secure today than they were yesterday, and they owe it to this "irresponsible disclosure." Do they have less of a right to security than the "unelite"? We don't know whether this is already being exploited by someone else, and as you said, it could be weeks before an official patch. This release both lights a fire under Apple and helps a few people patch early or at least be extra-careful about what they execute. That's an "upside"... I guess it's down to one's own values and possibly omniscience to conclusively determine whether the downsides outweigh that.
A more responsible version of this might be to release the source of a kext that patches the issue concurrently with confirmation from Apple. Apple got a few hours' head-start, some people can patch early, malware authors will have to spend some time reverse-engineering a complete exploit.