You don't have to be invested in something to be unbiased.
How does the fact that he is not invested give him the right to spread false informations and throw dirt? When i see bullshit, i call it out. simple as that.
My opinion is as good as his. But my sources are much better and reliably researched and obviously not biased.
A developer defending his project with a blogpost that mostly seems preoccupied with attacking the authors instead of their argument is "obviously not biased"? That response makes them look even worse.