Also, the NES launched slowly across the United States starting with New York. (Contrast to today's international launches)
Plus they had several legal troubles brought on by fear of the Japanese rising in economic importance.
Also there were several cartridge storages during that generation.
It was only cold in the US. The NES launched a few years earlier in Japan where it was very successful.
The point is that if the NES was launched with the market conditions that we have today there'd have likely been several times a many consoles sold.
Also, the NES launched slowly across the United States starting with New York. (Contrast to today's international launches)
Plus they had several legal troubles brought on by fear of the Japanese rising in economic importance.
Also there were several cartridge storages during that generation.