They could be "not up to" because of lack of resources, probably time and/or money. I think that's what is implied, rather than lack of technical knowledge.
I got the sense that they meant "not willing" but I agree that's one of those English phrases that can easily be misconstrued towards the more negative interpretation.
That said, I love the detailed post and the interesting solution, and the commitment to performance!
> The maintainers of Gogo, understandably, were not up to the gigantic task.
I'm 99% sure they are "up to" (as in "capable of") doing so, they are just not "up for" it (as in, "will not do it").