I think this is a really insightful reply, and I tend to agree with you. But it still doesn't help me be any less taken aback when people assert that PhD's should only be obtained when you want to do original research for your career. If you want to warn people, that's fine, but just do it instead of phrasing it as if you know the One True Reason for doing a PhD. I grant that some people might just be trying to be pithy, but I've seen too many people take it too seriously to just give the benefit of the doubt to everyone.

> Now I've done my PhD, people often ask me "Do you think I should do one?" and the unsatisfyingly true answer is "I don't know, I'm not you"

I wholeheartedly agree.