I thought these were intended to be limited run products from the very beginning. People being upset doesn't change that.
They never claimed the NES classic was a limited time product until they had pretty much discontinued it. This time around they said the snes mini would only be sold through the end of the year, but that they would be doing their best to drastically increase production so everyone could get one.
The problem is that Nintendo is horrible at communication. So instead of saying something like
"the mini nes/snes consoles were always meant to be limited quantity items and we cannot guarantee that everyone will be able to get one. However, we understand that our fans would like to play the games found on these mini consoles even if they cannot secure one, so we will look in to releasing them as bundles on other systems"
they say
"our fans are amazing and have exceeded our wildest expectations. There was no way we could have prepared for the large demand for the nes classic. But don't worry, we are taking this into account for the future and will do everything we can to make sure they are easier to get next time around!"
or they could simply make more of them...