Unless I'm mistaken, I don't think he/she mentions open source at all?
At the same time it's better to have a working project and having the satisfaction of shipping than going in circles trying to appease everyones definitions of open source.
I think it's more "I've created a way to make your Github contributions into a poster." I understand where you are coming from, but it's a tad bit reactionary, don't you think?
If I created a website for you to turn a user's facebook activity statistics into a T-Shirt I would hope that you don't think it is contributing to facebook's monopolism of social media.
At the same time it's better to have a working project and having the satisfaction of shipping than going in circles trying to appease everyones definitions of open source.