The question is large and complicated, and people can agree to disagree. There's nothing wrong with tweeting vulns: The company is at fault, we can defend ourselves now that we know about the vuln, and it's a big PR disaster for Apple.
A past conversation: https://news.ycombinator.com/item?id=14009937
No, no it's not strictly more ethical. It's not even strictly safer, which should be an even easier question to answer. The baked-in assumption in your logic is that users have no options other than waiting to patch. But, obviously, they do, and keeping vulnerabilities secret deprives them of those options.
> There's nothing wrong with tweeting vulns
Those two statements seem to be contradictory. It seems to me there is still quite a lot of debate about which disclosure policy is best,
It seems to me the right thing to do is to tell Apple privately, tell them to either push a fix or put out some kind of release letting all their customers know how to mitigate this in the next, say, 3 days, or I'll just tweet about it. What's the downside? At the worst case, you just prolonged the status quo for another 3 days.