Yeah, TNG deserves full culpability for this. Go back and have a look at the first appearance of the Ferengi on TNG - it is obvious that the writers originally intended them to be devious and bloodthirsty, before deciding that none-too-bright arch-capitalists worked better.Monroe wrote:Sounds more like a mistake of TNG than ENT to make such a great trading Empire but never have met the federation.
I favour the theory that the Ferengi the Enterprise encountered were rogues who had decided or been compelled to explore well outside the Ferengi's standard trade area. Perhaps they were particularly ambitious traders looking for new frontiers - or maybe they discovered one of the dozens of ways Voyager used to suddenly jump tens of thousands of light years into Federation space.