It's worth saying that lots and lots of countries have gone through this conversion process, sometimes multiple times -- think of all the countries colonized by the British (and thus converted from their existing systems to the British measures), who then sensibly converted to metric at some point after independence.

All of them were equally wedded to the pre-change system (fixed in mental habits, etc.), of course; there's nothing special about the American situation.

There's obviously a cost, but it's most severe for the older generation (whose mental habits are so ingrained they have real trouble adjusting) -- even for younger adults, your brain adapts to the new system after using it regularly for a while. AFAICT (I moved from the US to a metric-using country 7 years ago) it's never quite the same as the system you grew up with, but I'm pretty comfortable with it now.

It's something like learning bad words in another language -- they never gain the burned-in power of expletives in your native language, but your ears certainly learn to perk up when you hear them, and you can use them perfectly well.

Summing up -- quit whining, America, switch to better measurement systems, and the difficulties will smooth out more quickly than you think. :)