They want one computer that does everything and lasts forever - not a niche device that has to be tethered to a real PC anyway.
Yeah, that's a lot closer to describing my mom - housewive all her life, approaching 70 - but since the kids left home she has gotten one laptop after another, and her use is actually quite sophisticated by now - certainly beyond "browser only". I did give her an iPod touch but her only interest in it is inflicting pictures of her grandchildren on innocent civilians while she's out on the town - she uses her laptop for everything else. She has no particular interest in spending money on something like a tablet.
And don't forget the generational thing too - I'm going to be the mythical "grandma" one day, and when I retire and have an empty nest I am going to tweak my gentoo box all day long :-)