I think the fear of not being good enough would be about as bad either way.

I think there are multiple different issues of "not good enough". From my own perspective I do believe that I have good ideas worthy of sharing but on the other hand I know that the quality of my writing ability isn't as high as I would like it to be. The writeup of the idea improves though letting the draft circulate and incorporating feedback.

On the other hand it wouldn't help in the same way for a person who thinks their ideas aren't good enough.