Post should really be called "Historical emacs defaults". Most of them were products of an era where those defaults were, in fact, the best defaults. Versioned backups were lifesavers before version control systems were ubiquitous and easy to use.
I'll also note that folks have been going back and forth about ^H & DEL at least since the 80s.
Also, little by little Emacs defaults are getting modernized. For example, show-paren-mode is now t and use-package ships with Emacs.
Hopefully, at some stage, make-backup-files will be set to nil. It is annoying to log into any server, launch Emacs and discover you have generated lots of litter. I think at this stage backup files should be opt in, not opt out.
I don't know how this works now, but in the past it was a problematic option. For example, if you used sudo and TRAMP to do some local administration tasks, it would store those files in your own account. This was a security issue.
Potentially a problem when editing any file with secrets, right? (though, tbh if your home directory is compromised you are in a lot of trouble already).
It's practically impossible for "most of them" to be the best, these apps weren't designed by unicorns. And your example is a good illustration: the solution to the backup issue suggested in the post doesn't do away with versioned backups (neither does the other approach linked), so the lack of VCS doesn't explain this bad default
I'll also note that folks have been going back and forth about ^H & DEL at least since the 80s.