[kyllo]

Do I think that it makes sense? No. I agree with you there. Can I imagine it? Absolutely. It's just how the industry does hiring.

It's pretty well known that Google's hiring process for SDEs is designed to select for skilled computer scientists--the type of people who could do something like implement a stdlib for a new PL if needed. Then, since they can afford to hire only great all-around CS people, they can just allocate people to projects after the hiring decision is made. Of course not every SDE job at Google requires that level of CS skill, and it's massively wasteful to put most people on projects below their skill level, but they can afford to hire that way just because they're Google.

As a side effect, other companies hiring developers are likely to just cargo-cult whatever Google is doing.