Just want to mention the Munich Linux thing. Before Munich committed to the tech refresh Microsoft sent all sorts of execs until Steve 'Monkey Boi' Blamer got involved and undoubtedly greased the sales funnel (did they have such a thing back then?) but the recalcitrant government client decided to go ahead with the Linux deployment. As someone mentioned in their post that the roll out failed as the workers could not access resources for them to perform their function. So moved they canned it all and MS was back in the game. I wonder how much was spent by MS when really all they needed to do (as was predicted by many at the time) was wait until the entire thing fell to bits and the customer came in from the cold.
Cost is the crux of the issue. It will be, as usual, the big corps that would have the ability to make Linux a viable business tool outside of 'just being a server'. If you can move an entire compute infrastructure off MS and onto Linux and not loose availability, integrity and confidentiality along side not loosing service management abilities and not impact negatively on performance of (user) role you could be a pioneer. Thing is though that this is all predicated on infrastructure that is usually a mix of on prem and cloud. So really in this situation the back end is not a driver but the desktop side absolutely is.
So how much does that cost?
That is what is not going to make Linux a globally ubiquitous business tool. It would be horrifically expensive and what are the benefits exactly?
From an IT ops view it would be a horror show of trying to manage an OS that changes far too often to test applications. Then there are the issues around managing the devices and user accounts.
Then regulatory issues could get in the way as well. In this I mean the issue of admin accounts. Users never get admin accounts these days. So when the shit hits the fan and you've been breached through a compromised user account the powers that be would question why a user has an admin account.
All these issues can be dealt with, of that I have no doubt. The question for businesses is if it justifies an exorbitant cost. I cannot see it happening, not over night anyway.
So yeah. Cost.