I wouldn't necessarily consider him pointless because two of his episodes are some of my favourite episodes in the show, and he's usually the voice of reason of other characters, mainly Twilight.
But I'd agree that they didn't give him strong motivations or conflicts by the time season 9 was happening.
Cozy Glow, for example, was completely pointless, because at least Flurry Heart got A flurry of emotions, one of the best episodes of season 7, a season that was very average for the most part. My only problem to that episode was that it should have been from season 6, not 7.