I disagree. I've Ubuntu LTS setup on my mother-in-law's PC since more than 6 years and it's been no problem. Very low maintenance, too.
All she needs is email and web browsing. I'm pretty sure as far as security threats are concerned she is vastly better of with Linux. The usual exploits targeted at end users simply won't work.
Choice of operating system won't affect whether or not people type away their details into random websites. Putting Windows and Linux in the same box and pushing iOS over them is also puzzling.
Why would someone's non-technically literate parents happen to be running a Linux distribution on their personal computers and why would that make them more susceptible to giving their details away than running OSX?
OS X - it wouldn’t make a difference. But, apps are tightly sandboxed with iOS and it doesn’t even allow some of the permissions that Android does - like intercepting phone calls and text messages.
Yep, it's still definitely considered one of the most secure consumer platforms both in fundamentals and in the practice of the number of bugs it's had.
No security is perfect, a small handful of bugs over the last so-many years is about as good as any platform can hope for.
If you're a CIA agent or run a bitcoin exchange it might not be good enough for you, but for most people it's a pretty good set of options.
ChromeOS is more secure and far less expensive than MacOS, although as long as you keep your parents off of Windows you won't have to worry about ransomware.
For non tech users, iOS is pretty safe.
Ipad + iPhone and you're good to go. Leave the notebooks and PCs in the 80s where they belong.