That's a good point. I haven't been off the continent, but I'd imagine that in most countries, the majority of cars are domestic (to that country).
In America, for example, you'd probably see more Camaros, Corvettes, and Mustangs alone, than all other foreign makes combined
But really, I think a lot of American "gearheads" probably grew up working on thier dad's Camaro/Mustang/Charger etc. and so have developed a certain taste for domestic brands. Anything different just has no appeal to them (and a lot of "them" are simply narrow minded). Many of the people I've talked to that don't like Japanese cars often complain about them having "no torque."
I laughed, however, when one such individual compared an S2000 to a Z06, saying "it may not get 120HP/Liter, but it gets better gas milage and out-performs it in every way" (we were discussing the benefeits of overhead cams, which I was for and he was against, claiming that overhead cam engines make too little torque compared to his LS1... he somehow forgot that we were talking about 2-liter engines producing upwards of 200HP, and not 5.7 liter ohv engines making 300+ lb.ft). Anyway, that is what I meant by "narrow-mineded": He defeated himself by comparing a 2.0 liter engine to a 5.7 liter engine which only outpaces the smaller motor by about .2 sec in the quarter (that was his main argument: that Japanese cars were slow in the quarter mile...)
So, like RyRy said, the NSX is made really to appeal to a Japanese demographic, not really Americans. But there are some intelligent folks out there that can recognize a good thing when they see it, be it American, Japanese, Italian, or God forbid... Brittish...