I think its a good idea from Ubuntu, however I highly doubt that the don't want go get into the "phone business". It's typical of Ubuntu to say "we want to move forward, we don't want to be in the race", they want to distinguish themselves as being innovators for the business not a competitor to it.
Which is a smart marketing move, I'll grant them. They also say that they where working with the "phone companies", what does he mean by that? Is Apple + Samsung working with them to get Edge on the market? Unlikely.
Why only supporters can get the phone in the first place is really two things:
1.They really can't afford to put this phone with this type of hardware onto the market by themselves.
2. To make it feel exclusive
If this phone would make it to the ordinary market I don't think many would buy it due to Ubuntu not being as well known in the world. What they'ed done essentially is to ask the people "How many want to buy this?", then they have an accurate number on how many they will sell.
They won't however get to their goal at 32 million, there are only 6 days left, and they only have 10 million raised atm. "This campaign will only receive funds if at least $32,000,000 is raised by its deadline. Funding duration: July 22, 2013 - August 21, 2013 (11:59pm PT)."
So it won't happen anyway. So I guess that random people just gave 10 million to Ubuntu for no reason.