I actually think the extent to which the Ferengi have become downplayed over the years by the fandom in terms of their villainy is ridiculous.
One thing TNG was consistent about over seven seasons was the Ferengi being credible enemies of the Federation. Only on DS9 did they turn into them into this 'caricature culture', where
everything had a profit motive and the idea of a Ferengi ever being any good as a soldier was laughed at (although ultimately proven).
Witness:
*
The Last Outpost (season one): Okay, so first impressions aren't good.

But these Ferengi make a credible go at fighting the away team in hand-to-hand combat. They've got some kind of energy weapons that can stun (and maybe even kill), they're devious manipulators (in theory), and they all have tattoos.
*
The Battle (season one): Daimon Bok is an evil, devious, manipulative bastard out for revenge. A Ferengi battleship previously entered battle with the
USS Stargazer and managed to take them on strongly enough that, although they didn't win the battle, the Starfleet ship was beyond repair and had to be abandoned.
*
Peak Performance (season two): A Ferengi battleship interrupts the war games exercise, and everybody on both the
Enterprise and the
Hathaway treat it like it's a serious threat.
*
Menage A Troi (season three): The Ferengi manage to kidnap one of the Federation's ambassadors right from her own home planet, as well as two trained Starfleet officers.
*
Rascals (season six): A Ferengi boarding party manages to take over the
Federation flagship with only a couple stolen birds-of-prey.
I could go on. But it's fair to say that, as far as TNG was concerned, they never
completely forgot the idea that the Ferengi were supposed to be
dangerous, nor did they ever stop making them a credible threat time and time again. As I say, only on DS9 was their culture... "explored in more detail", yes, but they got dumbed down also.
