I think you may want to look in the mirror....Quality? They're built in the same plant. Hopefully when the Pathfinders come out, they won't be as bad as the JX's have been so far.
Primarily and foremost, luxury vehicles are ostentatious goods. If one's self esteem is partially determined by the shape of the badge on the grill, great. Luxury vehicles can provide that functionality, but it's paid for in disproportionate ratios.