For each example you could throw at me of those people, I could counter it with an example of people that consider them to be overpriced gimmicks. And the very fact that they are not selling well outside of iPad suggest that only the fanbois want them.
I've always wondered about this. How is it that there were only enough fanbois to garner Apple 3-5% of the PC market, but enough to get 70%+ of the MP3 player market, enough to move Apple past companies with much more experience in handsets in the smartphone market segment, and now to sell millions of tablets?
In the last (calendar) quarter of 2009, Apple sold 3.3 million computers-- their best quarter ever at the time. In that same quarter they sold 8.7M iPhones.
Where did Apple, a company with such a vanishingly small share of the personal computer market, get all of these "fanbois" from? Is every person who owns an Apple computer buying 2-3 iPads and iPhones each? If someone buys an iPhone or an iPad without previously having owned a Mac, or any other Apple product, are they a "fanboi"?
The problem with your argument is that you're trying to prove a negative, and you can't. Even a handful of people who bought the device because they have a legitimate use for it establishes firmly that there is, at least theoretically, a legitimate use for the device. If it were not selling well one could say that those who have a need for such a product don't constitute an addressable market, but that appears not to be the case.
Conversely, any number of people who don't consider the device to have a legitimate use does not establish that to be a fact, since the assertion is of a negative-- that the device lacks any legitimate use. I'm not sure why you'd choose to frame your argument this way, since it precludes you from actually winning.