Replace Java with Go (not much of a change, all things considered!) and that's exactly what Google seems to be doing. It's a big problem for them in the long run because it does mean accruing a mass of technical debt that will not necessarily be easy to get rid of. You'd expect "smart" folks in a tech-oriented enterprise to do better than that, especially if they're unutilized otherwise, but it can't be easy to do that sort of management at Google scale.