One of my very first PR's didn't even get a comment and I worked hard on it...

Feels bad man, all I need is some kind of yes, thanks for this, or no, this doesn't fit the project goals.

After patiently waiting, went ahead and created my own gem! No response sucks.

Why does this happen?

Some projects are just not worth the love.
I spent a few weeks working on pull requests for a project. All entirely sane, useful, tested replacing code that is none of that.
The devs didn't like it because they don't like change (it's a legacy project) and they didn't understand the code I was replacing. So simply ignored.