> I'm guessing at the specific knowledge some of these employees have is valued, and they probably wouldn't take kindly to having to study for a coding test just to keep their job.
Genuine Q: even if the employees don't take kindly to it, does it matter?
Well yeah, otherwise they leave and take their friends with them. If that happens to enough of the engineering department Google is left with just a pile of IP and trademarks, and will have to scramble to fill those positions with internal talent (who will obviously not be as experienced in this specific field as the aqui-hires).
Acquiring the talent is a big part of these acquisitions, and it makes sense for Google to try to keep them happy.
Genuine Q: even if the employees don't take kindly to it, does it matter?