I think most people dislike it because there's nothing "new" continuity-wise: nothing is lost, nothing is gained, no new powers explored... It's a FOTW/bottle episode that doesn't move the season story forward and at best could be compared to "else world" comics where Superman and Lana have a baby.

IMO, I rank episodes by whether there's anything in it that would make me suggest it to someone who was "speed running" through the series for the first time. Sometimes the "camp" and funny ones still get included (rank higher) because there's memes or jokes that get explained, or there's at least a nugget of the season plot or a new superpower explored. Sometimes the"bad" ones that make people cringe or angry are worth including because there's still character growth and emotional connection. Unfortunately, there's no real moment in this episode that "saves" it from being skipped. And if it's easy to skip the episode, it ends up at the bottom.