There's a parallel and equally wasteful but popular practice of insisting on taking on CxO employees of a purchased outfit for some prolonged period, perhaps as insurance, except that you've got no useful or interesting work for them to do. Unlike Garden Leave they're not fired - one of my friends was even told they could expect a substantial pay raise, but the job is now awful so their goal will be to wait only until as many options/ bonuses/ etc. as possible have irreversibly turned into hard money and then quit ASAP.
It's like OK, I could do something actually interesting next week or, I could sit in tedious meetings with idiots for 24 months, then pay off my mortgage, and retire immediately with $$$$$. Ugh.
If you know you'll be dead in a year, obviously the former is the right choice. But you probably won't be.