I will pass absolutely no judgement on you because I have no idea who you are, what you do, what the quality of your code/work is, but have you considered that maybe there is actually something wrong with the pull requests?
With no references to examples if what you're talking about, it comes off as a bit of a temper tantrum. But that's just what it feels like, but I have no idea because I have nothing to look at to form an opinion.
Even if he's misguided, he's trying to contribute. His description of someone finding a problem with his code could be written by someone who is a poor coder and doesn't understand why. However, it also doesn't sound like the people who rejected his pulls were very convincing at explaining why.
I think the point of the article is that the pull requests he's made came to nothing other than rejection. Nothing about the experience led him to believe he should make pull requests in the future. Even if he's a poor coder, I think that's a poor result and is worth talking about.
With no references to examples if what you're talking about, it comes off as a bit of a temper tantrum. But that's just what it feels like, but I have no idea because I have nothing to look at to form an opinion.