When teams decide whether or not to replace their head coach, there are two distinct threads of inquiry.
1. Is my coach worth keeping?
2. Is there a better option?
When the answer to Question 1 is cut and dry, the answer to Question 2 is an automatic yes or no. For instance, Kenny Natt was clearly overmatched as an NBA head coach. He was not worth keeping in that role. So whether there was a better option was basically moot; there had to be a better option, even if you couldn't quite put a finger on who exactly it would be.
For Keith Smart, the answer to Question 1 is clear ... but in the other direction. It's clear that even in a small way, he's worth keeping. You look at DeMarcus Cousins under Smart, and you consider how important Cousins' growth is to the future of the roster, and you're sort of forced to take a long look at keeping Smart. He's not a disaster in other areas, though he's never shown an ability to put together even an average defense.
When there's legitimate debate to be had about whether the coach is worth keeping, Question 2 comes into play. By total coincidence, I've written up a ranked list of the best coaching candidates available or soon to be available. All indications are that the Kings will retain Smart -- it's not even up for consideration, apparently. Personally, I'm OK with that. But if there's a change of heart, these are the candidates we'll be arguing about.