Do dealers believe in their products?

Most definately!
Especially the ones that make them money.

The local dealers have different needs from the manufactures.
The big glossy (mostly TV) long time stereo dealer has a market share and to not carry too much of what the Bestbuy carries. They want to sell glamour, along with stuff that works. They sell what has a good effect on the $$$ bottom line.
Another long term dealer stereo, sells a few lines where he gets along with the suppliers. The stuff is good, long time in business and has a longstanding high quality reputation.
They have a small business, but manage to make it.
A third longtime local dealer has odd little new brands. Stereo stuff. They are strange... How they stay in business is hard to understand.
A fourth new stereo dealer carries a few classic brands no-one else carries. They try to be totally real, upscale stereo, straight shooters. They are still coasting on the initial investment. We'll see if they can stay in business?
Do any of these 'believe'
#4 yes,
#1 no,
#2 kinda,
#3 is anyones' guess

No not all do, I had Innerosund Eros stats and the local dealer loved them, when he sold them. I came back a year or so later and a new guy who never saw me was the salesman, he had nothing good to say about them, and wouldnt ya know it? they were no longer a dealer. Nor are they in business now!

I think some definitely believe in their products. Unfortunately, occasionally companies don't support these dealers. I think in the enthusiasts world some companies are based on the idea of one man or woman pioneering based on research and his/her ears. These companies like ProAc, Ayre, Cardas, ?Audio Research, and many others seem to support local dealers and allow them some freedom to sell the way they want to. Unfortunately, even some of these companies catch the money train and start marketing and demanding that their dealers sell the way they want them to. This happened to my local dealer regarding Ayre equipment. My dealer did not want to sell a few products that Ayre offered because at the price point he felt like there were better options or there were units that he felt offered more flexibility for the same or less money. The sales manager essentially said something like if that's how you feel then you don't need to sell Ayre products and took away the product line. Granted I've heard Ayre sales have been improved since the new sales manager started so if it is about the money it is hard to argue. It takes special dealers to stand by their "code of ethics" and not be strong armed into selling things that they don't "believe in". I also think it is great if companies understand that sometimes not every single component in their line is the best. I mean who wants the entire industry to turn into the Bose audio way of the world. I hope this helps.