weren't they inserting themselves even in cases where there was no available coupon? Finding the user a deal isn't "doing literally nothing", and the argument for honey inserting itself in that case is at least not crazy. But as I understand it, they inserted themselves in every case even when they very literally did nothing (no deal, nothing).
I do agree that's shady, but there's a good chance at least some of those shoppers wouldn't have converted because they thought to themselves "I'll wait to make sure I can get the best deal" whereas someone with honey was in theory "sure" they were getting the best deal because no deals were available and pulled the trigger. Obviously in some cases that wasn't actually the case, but either way honey DID contribute to the sale.
My point is the issue is not honey. The problem is affiliate marketing (specifically last click attribution) as a whole. Don't hate the player. Hate the game.