The headline should be "The One Project Per Month Challenge." For me, the term "Side-Project" implies that the goal is to generate revenue, which is not the goal of this challenge.
I realize that this is becoming horribly pedantic, but the term "side project" is used a lot [1][2] to mean: "Someone who works full time but also builds a product on the side in the hopes that it will one day generate enough revenue that they can quit their day job."
In the context of this thread (a complaint about negative comments) I thought I'd point out that the title had been changed from the original [3], and that the change could perhaps, for some people, cause them to think that this was about trying to generate income outside of their day job, when in fact it was about just doing some small projects on a timeline.