he needed to go he had been suspended by the team because he's an idiot
he had been suspended 2 playoffs in a row because he's an idiot
he's been suspended 3 times in the last 4 playoff years because he's an idiot
if a player is showing you over and over and over and over again that he's an idiot that player, no matter how good he is needs to go, because no matter how good he is it doesn't matter if he can't play because he'as suspended.
The trade is not a good one , in fact it is Dubas's worst trade as GM and I don't think that's up for debate.
However had he not blocked the trade to Calgary it would have been Brodie and Bennett instead of Barrie and Kerfoot and chances are that deal would be looking a lot better.
Look what Bennett has done in Florida I believe he has a similar impact here considering that he'd have Matthews, Marner, Tavares, Nylander and Rielly around him here.
The trade didn't work out but that doesn't change the fact Kadri HAD to go he proved himself to be unreliable