I've had multiple people thank me* for writing about my recent emotional stuff (which is under a filter purely so that Julie (and her family) isn't exposed to it, and people feel they can comment without having to worry about that**).
And I do it to connect with people, and to share things I've learned in case other people find it useful, and to have other people tell me if I've lost the plot, and to be as honest as possible, so that I know where I am.
It helps me, a lot. Years of writing things about my emotions have been incredibly useful for helping me get to know me better. And I am still surprised on a regular basis, both by what I learn about myself, and how much simply writing down "I don't know what I feel X" leads to me knowing why I feel it.
It's not for everyone. Some people find that they focus on an issue, and all writing it down does is mean they spend longer dwelling on it. But if you're not that kind of person, then you may find it's a useful exercise. And you may just help someone else.
*And I'm not saying that to brag. You can learn things from almost anyone, if they share. What makes me unusual is not that I have particularly special thoughts, but that I write them down publicly where any bugger can read them.
**You'll note that this post is public. Act accordingly.
Original post on Dreamwidth - there are comments there.