People get involved in open source for a lot of reasons. For some, it's their job. For others, it's to scratch an itch. People don't get involved for a ton more reasons.
Yegor Bugayenko of Teamed.io recently wrote a post titled "How Much Do You Cost?" on how people mis-estimate their hourly value, and the criteria he in turn uses to evaluate them. He covers several areas to form his evaluation, one of them being open source contribution. The good thing is that if you don't have any open source contributions to show for, Yegor gives three explanations why you haven't done them.
First, you're too shy to share your code because it's crap. Obviously, this is not a good sign. Not because your code could be bad, but because you're not brave enough to face this fact and improve.
Well, of course it's not a good sign! You're shy and you do bad work! It's a good thing there are two more reasons after this one - there's still hope.
The second possible cause is that you work from nine till five, for food, without passion.
Your employer is maybe paying for open source in one way or another, but have you paid the price? Even if they don't pay you for it, surely you have about 8 extra hours in your day and the entire weekend. This is modern software development, either you're in or you're out.
Pick your head up and put that crappy code out there!
The last possible cause is that you don't know what to write and where to contribute, which means lack of creativity.
Do you have to be told everything? Have you ever used some code and it just did its job? Yeah, right. You should probably go out of your way and improve things or find all the bugs, just because.
Come on, you have to get that crap code out there somehow. Sittin' there being all shy isn't going to bring the bugs out.
The justification for wanting non-shy non-crappy developers is that they have a very high bar when it comes to code quality, which is not really related. Bravery shouldn't have anything to do with code quality, unless you're looking to hire people you can shame and yell at about their code...which is how it appears to be when "you won't feel comfortable in our projects" comes after mention of negative feedback.
The paragrah about passion, which oddly isn't at all about passion, is quite telling. It reads more like how people get into gangs. The paragraph is about your use of personal time, not about your emotion and feeling toward the problems you're solving. Passion is something that really comes through in conversation, not in commit count. How much and when you work on something has little to do with passion.
The paragraph about lack of creativity contains very little to do with creativity. The features you want for a project don't always line up with the project. Sometimes they're just not good ideas. That's a thing that happens. That all results in code not being written, thus a seeming lack of creativity.
The sentence about finding, reporting, and fixing bugs ignores all of the problems people constantly run into with open source contribution. Finding bugs can sometimes be easy. Reporting them is sometimes easy. Fixing them is usually harder, but getting them accepted and into a release often requires a significant amount of effort. To then minimize the struggles all sorts of people have gone through, especially socially, by putting it like "you couldn't do this?" is just sad. That's their loss, as plenty of super smart people don't have time for kiddie games on the internet, or people who would carry this attitude.
When it all comes down to it, I'm fairly shy and write crappy code. I wonder how much I'm worth.