You forgot one important(sic) catagory
Those who speak out of their backsides namely, the Analists.
They more than ever think that product sales will rise exponentially and give their tarot card readings to the market which drives the stock price. Guestimates at worst but are more influential at driving a price than sales figures from a company.
As for the iPad... IMHO, it is a mature device in a mature market segment.
It works and I see more and more being used in business especially the unloved iPad Mini.
I do all my presentations using a Mini (+ TB to HDMI dongle)
Thr aspect ratio is perfect for 35mm/DSLR pictures. Not everything is in HD Widescreen you know.
Is the iPad done? Not but it is more of a niche product like most tablets.
As for the Amazon Kindle... It worked up to a point. That's why I got the iPad.