It is a tough business indeed, especially when a company doesn't understand the market in terms of what can be offered (the company's expertise), what customers are desiring, and the potential for selling that product into the intended market. This portion of the business plan is essential, and too many times it seems like companies offer products with inferior market intelligence...where the rubber of reality hits the proverbial road.
Buell Racing was unfortunately targeting a small(er) market with a lot of competition (as Richard points out). They seemed to have the other aspects of the business accounted for, except for the part of selling enough product at a profitable price point to stay in business.
Brammo's demise seems partly due to a lack of understanding of what the market wanted/wants and was/is willing to pay for. Most of the early adopter segment has selected Zero's significantly over Brammos (either Empulses or Enertias), as we know because Brammo's sales just wouldn't take off and Zero's sales propelled them forward.
Case in point, I remember about four years ago that Brammo hired a sales executive from H-D to run their sales department. This was when they had about 10 dealers nation-wide to distribute their motorcycles. I then saw them franchising some H-D Dealers (on their Dealer locator webpage), and a few of the exotic motorcycle dealers in locations that could support sales of those machines What were they thinking ?? That really showed that they didn't have a good understanding of who was going to buy their electric motorcycles and how they should try to reach and sell into that market.