He - like many of my friends who became professional mechanics - is fairly conservative when it comes to factory up-sells. The X-REAS is complicated, and costly to fix/replace. There's an argument to be made that it works for a small(ish) percentage of owners who really do 4-wheeling stuff in stock vehicles, but even then, most of those guys upgrade way beyond stock. Plus the factory Bilstein suspension on the lower trims is really good, and not prone to problems.
Don't know why he isn't a fan of Fox, but I'll assume it's similar. They have a ton of experience in moto and mtb, but aren't legacy in the auto world.
On a personal note, with the disclaimer that everyone here knows I'm a huge Toyota fanboi, our current 5th gen (off-road premium) is an absolutely fantastic vehicle for our needs. Yes it gets terrible gas mileage, and yes it's louder than a luxury car/suv, but snow+skis+dogs+bikes=no problems at all.