It's out of the way for people who don't care. It's there for people who do. I've seen folk go "that's so cool" when the amazon stuff came up.
This stuff is much closer to the adds folk get in Google search. It's often relevant to what they're doing at the time.
The key difference being, with google I am specifically searching the "world wide web" and may type something that suggests an interest in making a purchase. Companies can bid against each other to decide the value of these searches.
When using unity dash, I am basically searching for programs that are installed on my computer. Or occasionally for a file. Doing a primitive text match against "thunderbird" with an online catalog is unlikely to help.
Once you are in this mindset you start to think "why should amazon get special treatment?" and you say "hey, we should search ebay too and what about netflix and pornhub?" and suddenly you have an entire screen full of crap and are leaking information everywhere.
This is why I sad "a chunk of people" not "everybody". I don't like it either. If and when 12.10 works on my laptop I'll kill it straight away.
My partner, however, likes it. She's often searching for book refs and amazon stuff. This makes her life easier and better.
Just because a group of people don't like something doesn't necessarily make it a bad UX. The mantra of everybody in the UX profession is that "you are not the user". My likes and dislikes do not matter if I am not the target market.
Does it matter if N techies hate something if N x 100 in some other larger group love it to bits?
Once you are in this mindset you start to think "why should amazon get special treatment?" and you say "hey, we should search ebay too and what about netflix and pornhub?" and suddenly you have an entire screen full of crap and are leaking information everywhere.
If and when that does happen - that'll be bad.
Hasn't happened so far with Google.
I don't see the Ubuntu folk being dumb enough to make that happen on their platform.
12.10 seems to take the opinion that every search you do should search everything by default, not even google does that.
If they are going to follow this model with Amazon, there isn't really any reason to believe they won't do it for anyone who offers them a sweet affiliate deal.
Time will tell.