I think it's worth pointing out that regardless of what is true or not true, Google has spelled out their interpretation, and their explicit and (exact quote) "aggressively-broad ban" on use of AGPL software within Google.
Beyond the legal implications of software, there are social ones too. I admit that I'm reluctant to use AGPL software when a differently licensed alternative is available, just out of a general stigma around it. I'm not defending that stigma, far from it, but I think it's fair to point it out, and point out that big corporations like Google are very, very allergic to AGPL (whether it's legally warranted or not)
AGPL only differs from GPL with regard to services provided over networks, which doesn't really apply here. Beyond that, AGPL is no more viral than GPL. So "there's no linking exception in the AGPL" is really irrelevant considering that there isn't one in GPL either, and I'm sure Google uses GCC.
Yes, there's a stigma against AGPL, but a blanket policy against using AGPL'ed software will occasionally ban something totally unproblematic, which is the case here.
Beyond the legal implications of software, there are social ones too. I admit that I'm reluctant to use AGPL software when a differently licensed alternative is available, just out of a general stigma around it. I'm not defending that stigma, far from it, but I think it's fair to point it out, and point out that big corporations like Google are very, very allergic to AGPL (whether it's legally warranted or not)