Is it the dealer or the manufacturers behind this? Both. Manufacturers have always hated competition, especially if Tesla could be a better product with a better sales model. They prefer to compete on who is already there and not allow another car maker a chance to cut into their profit. If its a success for Tesla then the big companies may say "why aren't we doing that" and cut out dealers? So Dealer owners would then not want this as they would be cut out of their profit or dealerships completely as they would not be able to cut prices as much as direct operation.
Direct operations is not a new model. Apple has their own stores but sells at other dealers but they need to sell to the masses and they all have the same price point. Tesla does not want to do that at this time. Heck its there baby. If they want to sell their own product and then get bigger and other dealers want to agree to sell them , its an option in the future. For now, direct sales. I'd bet that if they grew larger and sold more, they would not want to hassle of selling and let a dealership take the risks but again they are small to car company standards.
Tesla is still selling to a niche market that can afford them. I love the looks and the engineering behind them. Hot looking roadster, good looking electric sedans with energy that could be charged with solar panels at home versus Volt or Prius looking cars (BORING!). Like a lot of people I would love to switch to a Tesla roadster or sedan but the truth is, I cant afford it. Hmm, under 20k or 100K? I'm with under 20K. Please, sell a Tesla around 20K and they would take over but they can't for now and their competition can. If they got bigger and had more stores to sell them, maybe the prices would eventually go down. The technology would improve. If any of the car companies could do a solution to the battery problem, we would then be part of the future of electric cars. (sorry, its a bit sidetracked from the topic)