You would need to show incredible evidence for this -- the distribution of America's wealth has fluctuated greatly over the last century, and can be clearly linked to government policies, social trends, etc., and certainly has not been constantly shifting towards the wealthy, nor were the 40s to 70s devoid of technological development. (You could argue the last three decades eclipsed them, but I would have to see that argument.)

More generally, throughout history, the growth of the middle class has clearly been a key driver of consumer technology.