Comment by bryanrasmussen

>It's been a few years since I've had battle Safari quirks, one example that stuck with me from a couple of years ago is that LocalStorage is not available in private browsing mode. Other browsers just treat it as ephemeral/SessionStorage basically.

so what's the spec say people should do? Does it not specify?

Well I have known a few things on accessibility and color spaces where Safari was way ahead for a good length of time so my theory has always been that they were ahead on the things they cared about and behind on the things that they didn't care about and depending on what you cared about they might seem like jerks or heroes.