I know how Googlers justify it, I used to work there. But it's bizarre. Their codebase is highly modular but it's as if they forget all about modules, interface

I know how Googlers justify it, I used to work there. But it's bizarre. Their codebase is highly modular but it's as if they forget all about modules, interfaces and so on the moment they talk about releasing stuff as open source. I long ago concluded the actual motivating factor is that it's more fun to write new code than refactor existing code, and especially, it's more promotion worthy.