@ mark l 2 -
>
lack of apps
<
###################
tl/dr: lack of useless apps
###################
OK. I've got to out myself on the other side of the public opinion here: I would welcome this.
I tried the first Unity interface and hated it and it went after 2 days. 3 months later I tried again and still hated it and replaced it with xfce. When 12.04 came around I thought "wait, give it a real chance, man, you hated Windows 95 too and it was quite usable in the end" and promised to keep it at least 4 weeks on my everyday laptop. And I started to hate it less. It's different, OK. But not inferior; and some things actually work better for me using Unity. I now think it's rather nice. I find it less confusing and more intuitive than going from any other, essentially still "Xerox Star"-like, GUI to The-Interface-Formerly-Known-As-Metro of Windows 8. I do understand that a lot of people dislike it big time, but I think that it's actually a "change dislike", not something specific. I'm breaking a lance here for Unity; give it a real try.
Oh, and by the way: The Amazon search integration i s pants, but as it's possible to turn it off I don't see the problem! We're all doing the same thing when we install a new Windows on a PC: If we don't scrap IE altogether, we go through the settings and nail up the holes. Same thing, I think.
But back to mark's comment about the lack of apps.
Yes, you are right. there will be less apps on Ubuntu mobile. Techland once counted the number of "fart" apps in the Apple AppStore and came up with over 1100 (!), all of which will be missing from Ubuntu mobile (I can live with that.). And just how many "I can drink beer/ latte/ wine/ whatever-it-is-that-Bear-Grylls-drinks with my iPhone"-Apps does one really need? Some of the more popular time-and-byte-wasters might even be ported, I'm thinking of the likes of Angry Birds here. While it's not useful, it's at least mildly amusing.
Other than that it would run stuff from the Ubuntu software repository, which is not bad at all for useful stuff (and most of the useful stuff even for free). And that would make it better than Windows RT, which does not offer the same compatibility to it's desktop equivalent.
Just, as always, my own personal opinion on this; feel free to disagree, but try to keep an open mind about it . . .
If you find any typos, you can keep them, cheers.