Re: Strange way to respect user privacy
"suddenly have no industry-standard software applications for all of the employees to use"
That is a valid concern, for the cases where you have some users who do need those particular applications, and it is an important one.
But not everyone in every workplace necessarily needs those apps. In many cases, alternative but comparable programs do exist. It all depends on how deeply an organisation has found itself trapped in the data format lock-in quicksand.
In my workplace, we have a three-way split between Windows, MacOS and Linux. It's not an equal three-way split, but much closer to it than you might think, maybe 50 : 30 : 20 (not including servers), and most of the specialist apps that are in use here (including some that are commercial software) are available for all three.
"and no ability to centrally manage users, policies, restrictions etc"
Nope, various Linux computer management systems exist.
"I'll then spend most of my time pissing about with randomly broken dependencies whenever I try and roll out out any updates"
Huh? Distro repository managers and software management tools such as apt-get take very good care to manage updates safely; I gather that even in the rpm world yum can do a good job of this nowadays. And besides, you do test updates on test systems first, right?
"determine when drivers for a perfectly usable device are going to stop working."
No, that's definitely Windows (and to some extent, MacOS) you are thinking of ("We've changed something, and sod old code.").
On Linux, a device either just works (usually because commendable manufacturers have provided good documentation or have led or assisted with driver development) and, once got working, is very very very unlikely to stop working in later releases; or half works because it's compatible enough with an older driver; or simply doesn't work at all at the current time (cos shitty manufacturer even whose Windows drivers are also rather thrown-together, fragile, and barely work), and in that case at least there will usually be someone trying to make it work (at which they may or may not have success, but good on them for trying - and in the meantime, just don't buy that crap).
"Not to mention the man-hours, money and lost-productivity spent training the users and helpdesk."
None of Windows, MacOS or Linux are that different for end users (not admins, and untrained users shouldn't be doing that in a work environment) nowadays. It's the random UI changes to some programs (eg, MS Office) that are much more confusing for everyone. People can cope with their smartphone or tablet not looking like Windows, I think you are doing people a great disservice by assuming they can't cope with relatively minor differences.
And a competent support team should, where appropriate, have at least some degree of knowledge across all three mainstream OSes. Of course, if you just want to be a peanut-paying gallery of Windows monkeys, that's up to you, I guess…