I'll take him seriously on it. MacOS and Windows are terrible for professional purposes, for a number of reasons:

1. Requires Windows Pro or Apple Developer license to unlock full featureset

2. Cannot reasonably disable targeted advertising or ad data collection from either OS

3. Neither come with package managers and do not respect third-party packaging either

4. Can be "managed" insofar as your buggy CPM software allows, often glitched by the OS itself

5. The experience is always getting worse since Apple and Microsoft share a united front of making people spend as much money on useless shit as humanly possible

Now, that's not to say nobody should use these OSes - certainly people are locked into them for some purposes. But as a programmer it's genuinely hard for me to be productive on these OSes because I end up fighting them just for everyday, non-programming purposes.

I think it's entirely possible that MacOS and Windows can be inherently terrible experiences while also being mandatory for certain workflows.

Most professionals use only a handful of software and don't really care about the OS other than what the OS should do (file management, connecting to the internet, launching software,...). Apple and Microsoft insists on doing other stuff that impedes you while not allowing you to do basic stuff you want. The main issue with Linux is hardware support (which no one other than the manufactures can solve properly) and professional development (The distributions are great, but monolithic development like FreeBSD would have been better).

Linux is best because it lets you use your computer for whatever workflow you need.

I'm a professional who is often forced to suffer Windows nonsense. At work Windows routinely wastes my time with absolute bullshit I couldn't care less about and which makes me negative dollars, even though it is basically a glorified Chrome launcher.

Professionals should absolutely take it seriously because time spent updating Windows or even just waiting around while it gets its shit together is time you could have spent doing your job and making money. In fact, Windows and its spontaneous updates with obnoxious focus stealing prompts are major risks to the integrity of your work and might cause you to have to redo it from scratch, lowering the value of your time even further.

Linux boots in less than ten seconds and is already ready to use. There are distributions for all levels of expertise, and if there's an IT department it should be managing those boxes anyway. All that's missing is the Microsoft Office suite and in the end that's what the Windows vs Linux battle always boils down to. People put up with it because they just need muh Excel.