And I say that the average person does mind, especially when they find out. We don't have to agree. That's just been my experience since HD displays have been introduced. People switching from pretty much any resolution display, other than XGA, are surprised by the extra scrolling required in most applications or are happy I pointed them toward an HD+ or FHD display.
Now that I understand exactly what you "disagreed" with, I have to sort of agree with you. Yes, the average person does find 1366x768 too short, but doesn't mind enough to be willing to shell out several hundred dollars extra to go for a 1600x900 laptop. The cheapest 15.6" 1366x768 laptops are $250 to $400, whereas the cheapest 15.6" 1600x900 laptops are over $700.
And yes, I think we do agree that 900 and up is a practical usable minimum. I'd love an HD+ or WXGA+ on my X100e.
I believe I would be happy with 1600x900 but am actually not sure, because I have never used 1600x900 or 1440x900 for that matter. I have used 1024x768, 1280x800 and 1366x768 a lot and all these are way too short, and the next lowest res I have used is 1400x1050 and find it adequate. I guess 1600x900 should be okay but won't know until I have actually tried.
EDIT: I just remembered that I had owned a Z61t with 1440x900 very briefly, but too briefly to tell if 900p was tall enough.