Good question, often wondered the same myself.
The thing that keeps me awake at night is how anyone can justify the expense. On one of the threads about the Ryanair takeover of Buzz, someone said that the monthly lease of the 146 was TWICE that of the 737. If it takes less Pax and costs twiceas much not to mention the additional running costs how did they ever think they could make money. I suppose that was why they got in the trouble they did?