A person should be careful with advice. Specific advice is not offensive. General advice is offensive. Telling someone to get a job, or that they should take better care of their life, or get help, without any specificities is to call someone incompetent without providing anything useful to them. It's a kick in the ribs, disguised as advice.- eatsoylentgreen here.
I went into a massive lull on giving advice. The last few times people have come to me with problems I've ended up teasing their beliefs out of them, reflecting them back, and trying to help them decide what they actually want. And then, after a friend said "If I didn't want your advice I wouldn't have posted where you could see it and left comments on." (or words to that effect) I've been tacking back towards offering more of my own perspective on things.
And I think that the quote above captures something important - that different advice is useful for different people. That some advice is useful in general - but even then it's very unlikely to be useful or true _all_ of the time. And knowing when to break a rule is always the tricky bit.
I think part of me feels that if the correct course of action is obvious then my advice isn't needed. And if it's not obvious then my advice is unlikely to be that useful without knowing the situation in detail.
Of course, most people aren't actually looking for advice, they just want someone to talk to while they work things out for themselves. And that, I seem quite good at.