I would say about 75% of projects are like that, they don't want or take external contributions or if they do the rules are often so opaque to doing so properly

I would say about 75% of projects are like that, they don't want or take external contributions or if they do the rules are often so opaque to doing so properly they often aren't worth the effort. The rest have been a mixed bag of unpleasant but ultimately taking the bug fix to one project where I and the creator had a blast of a time for 6 months after he just gave me commit rights after my second patch and left me to it once I said what I was building towards. I think the good ones that make this easy and fun are pretty rare, I definitely check the pull requests and bugs for any project before I consider contributing nowadays.