Writing is the easy part. I get stuck on the publishing part. I always worry that I'm going to publish something that people will dislike, and I think that reddit tainted my thinking in that way.
If the critique covers the entire article, either the person holds a different opinion (in which no one is 'right') or the premise of the article is false. Either way, it's good to hear why.
On the one off occasion that someone is writing hurtful comments (and you can't seem to get it out of your head), looking through that persons comment history often reveals a pattern of abrasive commentary and at least for me makes it easier not to take it personally.
If you have something to share, publish! There's always someone who will enjoy reading it, and that makes it worth it.
Some of my favorite posts here are my most downvoted.
I write a lot in this HN comment box and post and then immediately delete. Probably my favorite.
But I've written a couple of books and that kind of writing, re-writing, editing and publishing is radically different from posting online.
If the muses strike me just right I feel like I could write for ages though. Then it goes in a directory somewhere, never to be seen again.