Reading this thread, I had an idea about the Radiants thinking Honor betrayed them: we've seen Shards encouraging/goading humans to behave along the lines of their intents, and this might be a problem with that theory.
Consider:
Ruin repeatedly told Gemmel and Zane to kill everyone in sight, except in Zane's case Vin, who was crucial to Ruin's plan. Incidentally, this might support the theory that a Vessel is able to temper his Shard's immediate inclinations, when there's an endgame that fits even more with the Shard's intent. Secret History spoiler ahead, just to be safe:
Ruin also controlled the Inquisitors to kill around with a happy face, and gloated to Vin that everything she did actually helped him. He was wrong, but of course he wouldn't even consider the possibility of failing.
Odium influences a lot of people, Shallan's father being a prime example. The Thrill is another way we see this.
Returned are supposed to give their Divine Breath to someone else, and you can only become a powerful Awakener if you convince other people to give you their Breaths; Awakening objects requires giving said Breaths to the object. Nightblood outright takes/steals Breath, though; this looks like an inconsistency.
Feel free to point out more examples
Anyway, my point is this. If Honor was throwing the Radiants into the meat grinder without them knowing it, then yeah, that was most likely dishonorable. But what if Honor just expected them to make the choice by themselves, and jump willingly into the meat grinder to save both the Rosharan people from Voidbringers (since we know there were Desolations before the Oathpact), and to save Cultivation from Odium?
Because that certainly would have been a very honorable thing for the Radiants to do, and it would fit nicely with the pattern of Shards nudging people towards their intent. Assuming that's true, I have no idea why the Radiants just got up and left at the Recreance; that would have been dishonorable. I'd like to hear your thoughts about this.