I can't recall all the detail, a large chunk of it bolied down to; having a proven track record, a device to show to ODM's in a working state, & to showcase the full potential of the sw.
Also IIRC one of the factors was that they wanted to ensure they had a regular revenue stream, they couldn't take the risk of relying solely on wealthy backers/loans etc.
And IIRC the original intent wasn't necessarily for it to be a definite long term thing, but after a short time it became that, as they saw so many inherent benefits...

They've detailed several times why it was important to them, & why it wasn't as simple as saying: Here, take our license for this sw & you -largely- take care of the hw & sell the end product.
That would've been their preference, as they saw themselves (& still primarily do) 1st & foremost as a sw co, but they determined it wasn't going to work -entirely- that way, for them.
To move forward they had to have device(s) in the game too, I remember vociferously arguing against it in the earliest days, I didn't get it, they explained a lot back then & thereafter.
Too bad I don't have a photographic memory, just CBF'd trying to find it in that last post (nor now), perhaps stskeeps will fill-in-the-gaps/refresh-our-collective-memories...

@stskeeps, I don't suppose you can flesh-this-out with lots more detail?
Update: He refuses to, oh well, if they want misinfo/misunderstanding around this subject to perpetuate, that's their problem.

Ubuntu Phone: Is It Worth It? (Aquaris E4.5)
https://www.youtube.com/watch?v=a0oQy7jgH_w

i cannot tolreate touchscreens with buttons on the front
look at n9 & n900 funny arent they
my first priority is no buttons on front or hell no bezels

like the swiping.

scopes are a waste of time, just as n900 widgets were.

if it was android we'd call it landfill.

os not as pretty as sailfish, but worthy alternative.

Oh, by the way, have you seen my latest n900 widget? It keeps track of the most recent podcast on a given RSS stream, showing you what it contains and letting you play it at a touch:

It's funny how corporations succeed selling crippled systems as "improvements" and masses swallow it, isn't it? No widgets? They were "outdated"! No status bar? We are "removing clutter". No more than 3 apps running (2 if one of them is a browser with more than one tab open)? That's obviously "improving user experience"

You know why? Os itself is no longer the main thing for the masses but easy access to serviceş. Most services get most users stop talking about Oses. Nobody cares

BR,
The mass

Yes, you're very right.
But the trade-offs they make are totally worth it for the average consumer who doesn't know how to place widgets, can't navigate the clutter and won't manage the running tasks.

I'm surprised everyday about the level of stupidity mankind can have.
I mean today I stumbled across this:
https://www.youtube.com/user/Lomak1581/videos

Flash Gordon sale coming up tomorrow...
Want an UbuntuPhone? Hit up the bqreaders website tomorrow at 8AM GMT — but you'll need to be quick! pic.twitter.com/DX2cEbbrrq

Funny what the russians have to do to get some road rules!