Oh I agree it had potential. It's the execution that is alas sorely lacking. I still think it would have worked better with young adult female dragons to sell the parallels better to Spike's usual situations, see also have Rarity not doing an embarrassingly awkward put up your dukes pose which wrecked her wonderful threat.And I would argue that Dragon Quest is a great exploration of Spike's character, specifically in terms of his search for an identity, and for teaching kids an important lesson about how "Family are the people who love you, not necessarily the people you share DNA with."
I don't think Over a Barrel was easily salvageable but Dragon Quest with a rewrite could have been really good. See also Testing Testing 123.