I would consider officials appointed by the regularly elected position of President as more democratically controlled than federal judges. If people dislike how the President is handling EPA rules, they can vote for a different president next time. Or voice their concerns to their elected Congresspeople, who could amend the laws. If SCOTUS rules in a way I strongly disagree with, I'm SOL. And, because of of stare decisis, that ruling is likely to stand for a long time.
>And also led to uncertainty - because these regulations were politically controversial and not supported by law, just by executive branch fiat, they are prone to being revoked whenever the party holding the presidency changes.
Firstly, Chevron Deference required rules to be reasonable interpretations of the law. So it wasn't total fiat. Also, there are other laws that prevent capricious changes. The new rule must be proposed, published, and allowed time for public comment.
Also, Chevron allowed courts to rule on ambiguous matters of law (e.g., how two laws interacted). Because judges are experts in federal laws. But for other questions, such as the dissent's citation of a case over whether a Pacific Northwest colony of squirrels qualified as a separate population from other parts of the country, there's no way I'd trust a judge to understand a crash course on biology, genetics, and ecology delivered by opposing sides in the span of a court case. Now imagine they do this all the time for different subjects. I doubt many judges look forward to these cases.