That is a really really shitty comment. Because their choice is different to yours they have a lack of knowledge?

FYI I had a top class developer working for me about 5 years ago, who saw me using WSL and VScode... they had a Windows machine and several macs due to the nature if their work. A week later they were on Windows every day, only using apple for apple builds.

The answer is, we don't all do the same kind of work. There is a reason so many engineers working in your field use mac. Guessing you are a Web developer?

It's funny you say this because the more I learned about mac the more I understood its limitations in being as good an operating system as e.g. Arch.

I know a lot of engineers. Some daily osx, some daily Linux. I'm not seeing any particular correlation in knowledge or skill - except perhaps slightly in the osx people's disfavor.