You make it sound like Amazon is put through the ringer for estimates like "2-3 weeks" or even "when more are available.". They aren't.
I think the most people are not upset they sold out, but upset that:
a) Many of them did put in the effort to get up (or stay up) and get there in time, and had to suffer checkout issues.
b) There is no Plan B, nor any other information coming out of Google. They are forced to go round the merry-go-round of refreshing the Play Store and waiting and waiting to see something change.
Most people just want to say "I want this, take my money when you can" and forget about it. It shouldn't take so much effort to give a company your money.