All that "articles"... MS has "site licenses" with yearly fee for long time. They have subscription versions of Office. And I guess they are moving forward, so introduce new forms of subscriptions.
But I do not remember (correct me if I am wrong) they ever had subscription ONLY versions of something. It was always possible to buy everything "once" (I am not talking about the price, but about a possibility).
Windows 7-8 will be "out of service" relatively soon, that is not a solution.
Changing to Apple is like moving from one prison to another. With MS you can at least choose the room, with Apple you can not.
Cockos was releasing Linux versions of REAPER all the time. But they was "just for test". They have many Linux port fixes recently, have made Linux board in the forum and "promoted" the download to the main page (still as "Evaluation"). I guess REAPER 6 will officially support Linux.
Also note REAPER is long time Linux+Wine friendly.
Tracktion has official Linux version for all products (but my experience with it was not good).
Bitwig has official Linux version.
Steinberg officially mention Linux is recent VST SDK.
Many VSTs are developed with JUCE, that means they can be compiled for Linux in no time (without extra development cost), if producers consider to do that.
So, if Cockos can release own (== well written) bridge to run windows plug-ins (current bridges are not perfect) and RME (Motu or some other player) can release Linux drivers, much more people can switch completely.
Note that "conservative" design of Linux (thanks to embedded and server solutions based on it) is perfect for "install once - run forever" approach. Desktop platforms (MS,Apple) tend to change the rules all the time to sell new products. Good for toys, one season clothes and may be for mobile phones. Somehow stupid for "hardware like" music workstations.