I'm pretty sure the parent was talking about macOS exclusive apps. The ones I recognize there are all multi-platform, which have always had the problem of keeping their own conventions between platform or adopting the platforms--most chose to keep their app consistent platform-to-platform.
I also think "professional" apps are a special case (which is a totally subjective classification). Even Apple and Microsoft have done their own thing for professional apps since forever. If I'm going to use that app for 8hrs every day, I'm more accepting of learning something new.
I'm still more likely going to pick up an app if it follows existing conventions...I already chose my OS because I've learned and like those conventions.