The main criticism seems to be that these 3 brands are overpriced versions of their parent company's respective versions of the same car. You might even take the argument a step further and say that buyers of these cars are overpaying just to have a better brand.

The irony is that these Japanese luxury brands undercut their German rivals (Audi, Mercedes, BMW) by thousands of dollars. And it's folks like me who are LESS (not more) concerned about brand that actually buy them because we recognize their relative value compared to German cars. The last six cars we've purchased have been Acura or Infiniti. And in every case, I looked at the German competition first because I'm a long-time German car fan (my family owned VWs and Audis mostly before graduating to a little BMW/Mercedes action). In every case the Acura/Infiniti was a much better value (i.e. what you get for the money).

I'm not saying everyone has to buy a car based on the best value. No way. Boring. But if you are going to criticize Acura, Infiniti, and Lexus please keep in mind that Audi, Mercedes, and BMW are charging a huge German premium for their brands. Part of this charge is based on Euro exchange rates but a bigger part of it is that the market is willing to pay more for less.