Why dealers disparage certain products?

To OP:

I completely agree, Roy.  You and I shared the same employer for several decades.  Bad-mouthing the competition is a losing strategy, but all too common.  Passing on anecdotes about the reliability or lack thereof of opposing brands is another favorite ploy.  No one can expect any dealer to have every line of product nor to have experienced what they don't deal in in a meaningful way.  But customers about to spend big bucks want to be convinced they are making the best choice.  Positive persuasive techniques don't always do the job, so the temptation to go negative is always there.  Witness the recent contretemps between Upscale Audio and Raven regarding their respective products.

@clearthink - he's in the business of selling gear to customers; I'm not. It's his livelihood, not mine. As a potential customer, if I don't like his 'individual style', I will respond to that style by applying my own individual style, which would be walking out of his store and never coming back. 

What about @hilde45 fanning the flames on the McIntosh fans?

Negative selling never works. Had a dealer in Baton Rouge that I was talking to about some Benchmark Equipment. I was considering a comparable offering from another dealer on Bel Canto. He lambasted Bel Canto and he is a dealer for the brand. Needless to say I will never shop him again and I have the BC gear and love it as I am sure I would like the Benchmark gear too.

@dinov So, you’re fanning some flames on me, but that’s not what I did, which was clearly explained in the OP and in subsequent emails from me. What you're doing is uncool and could easily be done to you. You don't want that, and neither do I.