I think they are simply advised to learn the 'hjkl' navigation because many of those already using have made good experiences with it. That's the nature of advice: Allow someone else to profit from your experience. But it's just that, advice, you're free to ignore it. I honestly don't see what's the big deal about it or why this in particular seems to irk you so much.

When I started out using Vim someone teaching me the basics pointed out the 'hjkl' navigation and recommended that I learn it, because I will be faster with it. Having to learn a lot of other commands, I kind of ignored the advice since it was simply a reflex for me to reach for the arrow keys. I happily used the arrow keys for years; nobody complained about it. At some point I finally decided to give the 'hjkl' navigation a serious try, and for that reason deactivated the arrow keys to help me break my old habit and take up the new one.

I would have found taking up 'ijkl' equally awkward, since either case I would have to retrain my muscle memory. Honestly, 'ijkl' and 'hjkl' doesn't seem to make much of a difference to me. Either one has to be trained a bit, and then it's automatic.

The one advantage of 'ijkl' that I see is that it forms a basis for the quaternions :-).