Now I wouldn't buy one, but you're presenting your opinion as indisputable fact, ts.
Samsung has sold north of 10 million Galaxy Notes and 5 million Note IIs, and those numbers are from the back half of 2012.
Since the first generation of the Note came out in late 2011, that means they sold around 15 million Notes of both generations in roughly a year.
That happens to be about the same as the total sales of Macs of all kinds in a year, recently (about 4 million/quarter).
So unless Macs of all kinds are a niche device, the Note's been pretty successful.
And the Note isn't even the only phablet, though it's no doubt the most successful one.
(All the numbers are from Wikipedia, and they all have sources there. If there have been massive writedowns by retailers on Notes, I haven't heard about it.)