I don't work there anymore, but this is a confused argument born of zealotry. Taking Google's money to work on open source is totally fine. More money spent on good things might even mean less spent on bad things.
For example, nothing good would come from the Go team quitting over unrelated political stuff.
Other than for commercial tool vendors like JetBrains, development tool improvements are rarely business critical in that way.
Go in particular is known for stability. In the short term, descoping or delaying Go releases is unlikely to matter to any business goal. Language and SDK improvements are for improving the ecosystem in the long term.
FWIW, open source is not an absolute good. It is undercutting the ability of your peers to make a living. It is making software a commodity, such that capital rich hardware owners can make a killing. See AWS.
It may not be common, but it is possible to make money on open-source software. Redhat would be the largest example. Automattic's WordPress is another.
If software can be profitable whether it's open or closed-source, then isn't open-source inherently better?
They continue to operate fairly independently, and there business is still fully open source. IBM executives have also paid lip service to their model, suggesting they might move towards it. (Of course, lip service is lip service, and action is action. Two different things.)
For example, nothing good would come from the Go team quitting over unrelated political stuff.