A holodeck serves a purpose because it can take you anywhere. They basically made a holosuite into another bar. Which they already had one downstairs. It would be like someone saying I got a bar but it's not good enough so I'll take the property from the guy above and make a new bar. That's basically what they did.
Nobody "Took" anything from Quark by making another bar in a holosuite because Quark owned the Holosuites, which means anybody using them has to pay Quark, so it's not like they're loop holing Quark out of his profits.
Whatever anybody did in Quark's Holosuites, be that some Orion Slave girl experience, fighting at the Alamo, role playing as a spy or visiting an advanced hologram in his own bar in the 1960's...... Quark still gets the business and the profits and whatever anybody does in his Holosuites isn't really anybody else's business.
I think what he meant is that Vic the character as well as his holo-bar took time/scenes away from Quark and Quark's bar. Sure, the holosuite Vic's was in was technically part of Quark's bar, but we're not talking about in-universe business and profits, we're talking about scene-stealing. At least that's what I think he's saying, I may be wrong though.