> Why was management pushing for it so hard? Better (existent) salespeople for microsoft vs OSS?
It's not clear to me. But it seems to have been part of a vision to "servicify" everything. Where everything should be a service "maintained" / "paid" but never "developed" to reduce costs.
Yes, that is also a thing at CERN.
Many other teams re-develop things internally (Linux based) because they could not trust or rely on IT management to do the right things.
That had a very perveted effect of internal duplication across teams and experiments.