Comments are usually easier to get than posts.

They're certainly lower effort, and posting can be intimidating. You're putting yourself on display for any to mock by making a post. I completely agree.

I was going to say something about encouraging posting, a-la "there are no stupid questions," but I don't really know how you'd do that.

Whatever works; maybe it's a good idea - as long as people don't get the idea that's the only time they can post questions.