Though I do admit that when they're 'on' as a couple they are really on. Ollie probably just needs more consistent writers.
Ollie and Dinah could both use more consistent writers. Dinah's been suffering more recently but Ollie has been consistently out-of-character for several years now in most of his appearances.
That only times I can remember either of them coming off as they should be anytime in recent memory was when Gail Simone featured Ollie in Birds of Prey and the wonderful little scenes in Final Crisis where Ollie complains about being drafted and the later moment in which Ollie sacrifices himself to the Anti-Life forces to cover Dinah's escape.