Because it costs more to build tha they are going to sell it for, and they want to limit their losses.
You have a link to that. I saw on the news, that the Volt's profit margin per car will be similar to their other GM vehicles. What they said also is that, due to the significant amount of resources contributed to R & D and design, it will take quite a few cars sold to make a profit!
I personally pray this will happen!
(1) GM Volt TAKES off, better than anyone dreamed! The 10K are already sold, and 45K of 2011 60K are already sold. I see GM bumping Volt production from 60K in 2011 to 200K.
(2) 2011 - I see Tesla (who is in trouble at the moment, after a huge boost in stock sales), finally going into production on their Model S. Getting it to public by 2012. With the demand created by the Volt, I think the Model S takes off.
(3) 2012 - With the Volt success. Mitsubshi, Toyota, Honda, Ford, Chysler, Kia etc start flooding the markets with their electric cars. Volt becomes the highest selling car in America.
(4) 2012 - With the BP oil spill have disaster effects, with oil countries like Venezuela and Iran causing problem, the President will innitiate programs to keep demand for the electric car hight. First, he will raise the electric car tax credit from $7,500 to $10,000 (possibly $12,500). With gas prices starting to dip, the government will raise the gas tax to keep gas prices high!
(5) 2015 - The Break Through Electric Car! Finally the all electric car that gets 500 miles per charge and fully charges in less than 15 mins hits the streets.
(6) 2020 - Electric Car tips the 50% mark on the street.
(7) 2025 - Electric Cars tip the 90% mark ont he street
(8) 2030 - Gas cars of a think of the past!