i disagree with the generalizations.
portability is certainly offered for traveling, but i wouldn't dismiss any portable machine (including the surface laptop) as something that's not suited for home use. plenty of people whose jobs don't require them to have a big screen real estate or power hungry software choose to get a laptop as their primary device. and there are laptops whose performance can rival a fully decked out desktop.
as for the surface laptop specifically, i also have no doubt that there will be plenty of folks who'll pick one up with the intention to make it their sole computing device.