I think this applies to every operating system -- most people don't "choose" operating systems, they just use whatever came installed on the device.
People don't choose Windows either, they just use whatever is preinstalled.
I think large numbers of non-technical people make a conscious choice of OS when asking 'do I get a PC or a Mac'. Familiarity, compatibility with apps, games etc. I've not met a non-technical user actively choose Linux (or not complain if it's pre-installed). It's an anecdote but backed up by the numbers.