I hate including WWW and love short URLs: but there's a bit of a problem.

Technical things that are trivial for people reading this comment: knowing the difference between right and left clicks, copying and pasting, using keyboard shortcuts to find a bit of text on a page, or even recognizing that a URL is a URL without the context that WWW provides, is hard for many non-technical users. Really.

There are some people who will not understand what "Visit us at no-www.org to find out more!" means unless you write out www.no-www.org.

(And even then, there will still be some people who are confused and go and physically type in www.no-www.org.com into their web browser.)

It must be so because often enough I see really ugly website addresses in ads like www.promotion.brand.com.

Why is this a thing? Why is someone trying to create a trend that we need to follow.

I make sure my sites work with and without www. In HTML documents it doesn't matter which you choose because the website address hidden in the link tag.

Verbally, I always omit the www, but when I communicate a website address via paper I prefer to use the www in order to make clear it is a website. I could use https:// instead but I like www more.

I think their "class B" makes the most sense: allow www, but redirect it to the same URL without www. I do that on my own sites, and no-www.org does the same. They explicitly say that making www not resolve at all "is not recommended for sites that serve the general public."

That said:

> I could use https:// instead but I like www more.

If your site uses https, communicate it with the https, because otherwise browsers will default to http. (That and get it on the hsts preload list so that some of them won't.)