Full disclosure...I've been an executive in the consumer electronics business for over 50 years. From small one man "on campus" HiFi sales, to Radio Shack franchise, to a 12 store pure HiFi chain to a 240 store publicly traded HiFi chain.
There are three reasons a dealer will disparage products:
#1...Some other dealer in the area already has the product and supports it.
#2...The dealer could not get a line of credit for the product and doesn't have the finances to stock and sell the product. And/Or the manufacturer requires a substantial financial commitment.
#3...He/She is an honest dealer and actually auditioned the product and decided to offer an alternative
(Rule #1 in retail sales....NEVER disparage a competitor or other products.....NEVER!)