Grandma: I'm typing domain.com into my browse on [random device] and it doesn't work.
Nerd grandchild: well that's because it doesn't exist.
Grandma: But it works on my other computer.
Nerd grandchild: that's because the browser tries lots of domains like www.domain, domain.org and so on when you enter domain.
Grandma: yes, I noticed that. When I enter www.domain.com, it automatically corrects it to domain.com. So that's must be the right one, surely?
Nerd grandchild: Nope. domain.com is the correct domain. It's just trying not to confuse you.
Grandma: ?
Things change. We've had something like 30-odd years of URLs. The people who can't deal with this are vanishingly small, and those that can't are likely not your target market; or they're the sort that'll just consider Facebook to be the web.
I'm not disagreeing with your point btw that some people can't deal with this - all I disagree is the extent.
24 from the RFC, 26 from the discussion that led to it, per Wikipedia.
We're going to see more and more changes that the "old folks of the internet" are going to hate. Some, or even many, of these changes will actually be good changes. We shouldn't prejudice on age.
Again, to be clear, I think this particular change is horribly broken.
PS: consider how you would guide an older person over the phone when he/she is accessing Citibank website (for which www.citibank is different website), with Chrome will "intelligently" hide essential part of the address.
And I am quite sure removing 'www' on the address bar's domains is as confusing.