Indeed, in DS9, Armin Shimerman as Quark developed sympathetic aspects and had some admirable moments. Nevertheless, although DS9 was the grittiest and most realistic of the Star Trek shows, even it shied away from anything that suggested a critique of the implicit naive socialism that animated Star Trek’s vision. The show runners no doubt knew that their essential audience of teen age and up boys did not want to see any tampering with the show’s formula of hot chicks, adventuring in space, and an eternal single life with no need to get a real job and take up the joys and burdens of marriage and raising kids.
DS9 was one of my favorites too. Covered topics about economics, religion, etc., that were ongoing on the station.