Some people can handle the nightlife scene, others get absorbed by it and it ruins their dayjob. We don't know what category Setoguchi fits under. We can see that his production since the trade has been in a spiral down.
Personally, if Seto has settled down some, I would have loved for his return to teal (especially at 1M or less). We need a #3RW and Seto could have filled that hole for this upcoming (throw away) season. I just did not want him leading any of the rooks into that kind of lifestyle. Still hope the best for him, hope he scores 20 on the flames (just none on us).
It would have been an excellent reclamation project with no real risk or cost in assets. I don't buy the takes a spot from a rookie nonsense, either. None of the kids (including Goldobin) look to break camp in a top 9 winger role anyway. And with the logjam of 4th line veteran scrubs DW just signed, not much room for kids to make the top 12. (well, one spot for McGinn or someone to replace Torres)
Heck, a line of Torres/???? - Thornton - Setoguchi would have been a fun experiment.