I would not say that Ollie has a bad rogues gallery, but I also wouldn't say he has one of the best. I felt that the Rebirth GA run did a good job of showcasing portions of it. Ollie also had some compelling rivalries with Prometheus and Deathstroke in the early 2000s even though they aren't primarily his villains.

Green Arrow's problem is that the villains writers create for him never return after the run they were created in ends. Kevin Smith created Onomatopoeia... who was an Ollie villain for one story before becoming a Batman rogue. Judd Winick created Constantine Drakon and Danny Brickwell, and Drakon hasn't made an appearance since his inception and Brick had to wait ten years to return to a Green Arrow title. Andrew Kreisberg created Cupid in his Green Arrow and Black Canary run, and her only other appearance is in Kreisberg's second run in the New 52. More recently, Ben Percy created the Ninth Circle, and following the established trend, they haven't even been mentioned since his Green Arrow run ended.

There are a few exceptions, like Clock King and Count Vertigo, but by and large, Green Arrow villains are created and then promptly forgotten about. It's not that these villains are bad, it's just that there's very little sense of continuity between runs regarding Ollie's rogues gallery. Writers ignore previous runs and create their own villains for their Green Arrow stories, villains that are then ignored in the next writer's run.