Quark I hate. Not just because he's ferengi he is just an absolutely horrible person. Literally noone likes him, he is never supportive or even happy or anything. And he gets WAAAAAAAY too many episodes and they are all exactly the same.
I agree a lot of the Ferengi focused episodes aren't that good, but in episodes that don't focus on Ferengi Quark's a great character.
How's he a horrible person? Because he breaks the law and cares about profit? He's also harmless, he doesn't kill people and goes easy on people when he sees suffering. And you're also wrong nobody likes him. Dax likes him and everybody else on the station wavers between liking him and loving to hate him.
Nowhere close to a saint, very acquisitive, but he's a positive force in the universe.