I do think we’re supposed to recognize that Rom is actually very skilled though. We see it through Nog’s opinion of him, and how well he does after he joins the Bajoran maintenance crew, despite his first initial awkward interactions.

He also invented those self-replicating cloaked mines that stopped the Dominion from coming through the wormhole and saved the Alpha Quadrant.

But still, the fact that the holosuites didn’t deteriorate after Rom quit working for Quark suggests the first possibility rather than the second.