True, dealers have powerful tools to reach customers now like never before. A bad
ebay dealer can cast a wide net, and there are sharks aplenty. But, the customer can call out the dealer too. Stupid
ebay can censor the "feedback", but we all have other tools to get the word out.
I recall many collectors at shows trying to push their bad purchases too, it is not unique to dealers. It is often just "sour grapes", or hypocrisy, when our friends complain about dealers.