I am not a Mac fan. In fact the complete opposite - I wouldn't touch anything made by Apple. I am a Linux fan though! The problem with Sonar/Cake is that, as others have said, to make it cross-platform would require a complete rewrite from the ground up. They would have to start by creating a cross-platform framework and then port everything through that. It could be done, but it would require a lot of time, devs and money. And for what? The vast majority of people use Windows. The comparatively minuscule market of Mac boys and girls will continue to use Logic. The Linux crowd won't be interested because there are very few Linux compatible plugins and audio interfaces at the moment. That may change one day though because Mac is losing its grip on its market and many die-hard Mac fans are starting to move away. Meanwhile, Linux is growing in popularity. Linux is actually the most used OS in the world. It's on almost every web server, every Android phone, TVs etc. but while it's growth in the user PC market is growing, it hasn't reached the kind of popularity yet where audio hardware manufacturers and plugin developers see it as a worthwhile market to chase after.

And not to forget a cross platform implementation would introduce a lot of new bugs, also in the Windows version.

If you would really like to see a cross platform (Win/Mac/Linux) DAW up close, take the Tracktion Waveform for a trial spin.  https://www.tracktion.com/products/waveform
 
Heck this thing will even run on a $35 Raspberry Pi 2 & 3 micro computer, running Ubuntu Linux: https://www.raspberrypi.org/
 
They developed this DAW using a framework called JUCE, by the original creator of Traction, Julian Storer https://en.wikipedia.org/wiki/Tracktion 
https://juce.com/
https://en.wikipedia.org/wiki/JUCE
 

With support for PC, Mac and Linux, JUCE is the perfect tool for building powerful and complex applications. JUCE also supports the development of plug-ins: VST, AU and AAX. Run your desktop applications on mobile! One-click deployment to Android and iOS (requires Android Studio and XCode) Adjust the user interface of your application with the Projucer live coding engine Use the best audio performance available on iOS and Android.

I hear you all when you say it is a complicated programming effort.  And there is the big question of is it worth it to the company. But this is not Hendershott-Cakewalk, Roland-Cakewalk, or Gibson-Cakewalk.  Bandlab-Cakewalk has a whole different approach.  The value equation might be different for them. 
 
However, Meng could certainly comment and end the speculation one way or the other. 

abacab
If you would really like to see a cross platform (Win/Mac/Linux) DAW up close, take the Tracktion Waveform for a trial spin.  https://www.tracktion.com/products/waveform
 
Heck this thing will even run on a $35 Raspberry Pi 2 & 3 micro computer, running Ubuntu Linux: https://www.raspberrypi.org/
 
They developed this DAW using a framework called JUCE, by the original creator of Traction, Julian Storer https://en.wikipedia.org/wiki/Tracktion 
https://juce.com/
https://en.wikipedia.org/wiki/JUCE
 

With support for PC, Mac and Linux, JUCE is the perfect tool for building powerful and complex applications. JUCE also supports the development of plug-ins: VST, AU and AAX. Run your desktop applications on mobile! One-click deployment to Android and iOS (requires Android Studio and XCode) Adjust the user interface of your application with the Projucer live coding engine Use the best audio performance available on iOS and Android.

I've been looking at Juce for a while now, but haven't found the time to play with it yet. It looks like a very decent framework for making VSTs too. The pricing plan is reasonable too.

marled
And not to forget a cross platform implementation would introduce a lot of new bugs, also in the Windows version.

And to make things more interesting, probably different bugs in the Windows version from the Mac one.

Then again...

Live
Studio 1
ProTools
Cubase
Adobe Audition
Digital Performer
Traktion
FL Studio.

All have Mac and Windows versions with the same or almost the same functions.

abacab
If you would really like to see a cross platform (Win/Mac/Linux) DAW up close, take the Tracktion Waveform for a trial spin.  https://www.tracktion.com/products/waveform

As a "trial spin" not bad. But after all frustrations and disappointments with Waveform 8 under Linux, I do not even checked Waveform 9. Linux version is at beta stage at most.
 
There is a good reason why REAPER has Linux incarnation, but has never released it.
 
Also all Tracktion software (including VSTs!) is calling home (not configurable, developers claim that is "by design" to keep users up to date).
 

Heck this thing will even run on a $35 Raspberry Pi 2 & 3 micro computer, running Ubuntu Linux: https://www.raspberrypi.org/

After behavior on normal Linux, I wonder if it not only "run" but can also really "work" there..
 

They developed this DAW using a framework called JUCE, by the original creator of Traction, Julian Storer https://en.wikipedia.org/wiki/Tracktion 
https://juce.com/
https://en.wikipedia.org/wiki/JUCE

With support for PC, Mac and Linux, JUCE is the perfect tool for building powerful and complex applications. JUCE also supports the development of plug-ins: VST, AU and AAX. Run your desktop applications on mobile! One-click deployment to Android and iOS (requires Android Studio and XCode) Adjust the user interface of your application with the Projucer live coding engine Use the best audio performance available on iOS and Android.

Interesting and innovative concept, many VSTs are developed with it... and as a consequence:
a) blind musicians can not use these plug-ins ("commercially not feasible to support accessibility")
b) VSTs are way too big and "heavy" then they could be, but multi-platform and look modern.
 
I was fascinated by Tracktion/Juce, but in the mean time I am not sure what I think about them...
 

For standard cross-platform apps, I use the Xamarin framework which is amazing. I especially love the way I can compile on my laptop and it automatically connects via ssh to my mac mini and compiles it there.
 
How it would cope with with high performance audio is another question tho, and I doubt it's the answer we'd want.
 
M.

Every time the discussion comes up to make Cakewalk MAC compatible I think back to when Adobe did it with the versions after 3.01. They did get it up and running but in doing so had to remove a lot features for both PC and MAC, some of them never really came back. While it would be nice to see Cakewalk take advantage of another OS, I would hope that it doesn't come at the expense of program features that would neuter it for PC users.
 
 

emwhy
Every time the discussion comes up to make Cakewalk MAC compatible I think back to when Adobe did it with the versions after 3.01. They did get it up and running but in doing so had to remove a lot features for both PC and MAC, some of them never really came back. While it would be nice to see Cakewalk take advantage of another OS, I would hope that it doesn't come at the expense of program features that would neuter it for PC users.

 
Do you mean DX plugins for example...? Anything else?