Linux is ready for workplaces and has been for a very very long time. That is irrelevant if workplace IT support is not ready for Linux and has no budget or time to get ready for it. All your points are meaningless and have never been the problem. The problem is with management, policies and getting in house support for things and all the work involved in that. Depending on the size of the company it can take a lot of time effort and money to retrain IT staff to support Linux. And IT staff are already overworked, under-budgeted and don’t always have the time to support extra things.