> This attempt by the Gitlab folks to ride the Github dissatisfaction
> wave seems a little low-brow.
There's a github dissatisfaction wave?
Anyway, opening sentence of gitlab's open letter: "The letter of GitHub’s open source community is clearly not addressed to us, but we’re thinking a lot about the issues that were mentioned in it."
Does that cover your concerns?
I think if github was the free software entity, and gitlab had no free software edition available, then the tone would be, as you suggest, totally inappropriate. However given the arrangement is the other way around, it seems quite reasonable they would hop onto this issue at this time, especially given the very clear caveat quoted above.