But he also wrote Smash the Mirror, which was pretty decent. I don’t think there is a rule to which writer writes good episodes and which one writes bad ones. Even A&E had bad episodes (511) and Jane Espenson (503).
What’s funny is I too actually looked at the body of work for Jerome Schwartz on OUAT and overall was quite happy he was writing this episode. As you pointed out, he worked on Smash the Mirror which I enjoyed, Enter the Dragon was a miss I think too, but he worked on Sympathy for the De Vil, which I thought was outstanding. And this season, he did do Broken Kingdom. Funny enough, I enjoyed broken kingdom mainly because it showed that Snow and Charming aren’t total idiots (and I didn’t get offended like some people did and I think the guy who played Arthur did a solid job of portraying the cry baby obsessed, manipulative child that Arthur was). And then, he worked on Birth which I thought was very good. Overall, I’d say I’ve enjoyed the episodes he has done.