Unless my eyes are just completely missing it, I didn't see anywhere that they said or implied that they weren't using macOS or iOS on their Apple devices.
People often say they are happy to pay a premium for Apple because of the software. So, for someone who doesn't use the unique features of a particular OS+apps bundle maybe they could use another ... which reminded me of the lawsuits that resulted in Microsoft [partners?] having to refund the OS portion of the sale price for those who chose not to use Windows.
It was a leap, but not a huge one IMO.
I know a lot of people who have MacBooks of various types who use Chrome as their browser (and only access their mail through the Gmail web interface), MS Office, etc, rarely using a single one of the Apple bundled apps (save perhaps the very basic ones, like Preview)...and yet, they would never give them up for a Windows computer, because so much of the OS is very fundamentally different to interact with.