I think the visibility is important. After 20 years in the workforce, I've learned that it's more important to be liked than it is to do a good job. If people work from home, the managers have trouble knowing who to keep, and who to lay off, because they can't interact with you socially in person.
> Getting rid of good workers because you don't personally like them? Keeping your mates even if they're useless?
Things are rarely so clear-cut. Usually there are shades of gray and humans tend to develop affinity for the ones they interact with in person. So if two colleagues are similar in performance, one in office gets preferential treatment due to unconscious bias.
It might be working as expected, even though the number is quite high, maybe higher than expected. The problem I see is when they do need to hire later down the line, it will be much harder to convince people to move when the change in work/life balance is that drastic.
I agree. Usually your best people have an easier time finding new jobs and are the first to go. That will also work against future hiring when you no longer have the talent to draw in great people.