I don't even use Ubuntu for the desktop or the laptop, what motivation do I have to use it on a phone or tablet? How about making Unity less than an unholy mess before branching out into other form-factors?
- build apps or port apps to work better on it. I can also do this without having to resort to Java like Android if I want to do things the recommended and supported way. I am also guessing that running su/sudo on it will not feel like an ugly hack to do like it is on Android[1] since it should be built in.
- run scripts (you can do that on Android with the Android Scripting layer and the terminal emulator, but it still has its quirks).
- easier access to things that are harder to deal with on Android or iOS (development tools) via apt. Perhaps even something like Blender or Gimp will run decent on it.
There are lots of possibilities. Perhaps not if all you want to do is browse the web and check email. However, I consider it another way to hack around and build things.
[1] http://www.chainfire.eu/articles/125/_How-To_SU_published/
I just loved the comments and insight on here and felt I shouldn't post much unless I really felt I had something to add to the conversation. If you haven't yet, I recommend reading the FAQ area[1] about posting stories and comments. It's really good information that seems to get skipped over sometimes.
Also, welcome to HN :)
Can't you make this argument about anything?
No one is forcing you to use it but it still has potential to positively affect your tablet experience, even if it's indirectly.