The HE didn't fail. I think they are just clearing out the leftovers to bring out an overhauled synthetic stock next year, just like on their new scout rifles.
A few years from now, all those RARs will be so much cannon fodder, but the HE will be coveted.
Americans buy cheap junk when it looks like a good deal; they then buy something more worthwhile when they desire to move up in the world. Most RARs are being bought by new/young shooters.
Regarding your perspective on the RARs, I had hundreds of more expensive rifles when I bought my first RAR-Predator on 02/05/15 and have since bought 8 more. I have been shooting for over 50 years and am currently near the end of my 6th decade on Earth, neither new to the sport, nor particularly young. Perhaps I'm not representative of the "typical" RAR buyer, having liked them enough to buy 9 of them.
What rifle can you buy for under $400, often under $350, that offers such good out of the box accuracy as the RAR-Predator? If somebody makes one in 6.5 Creedmoor, point me in the right direction.
