This is not a shooting percentage metric.
This is a points per possession. KC suffers here because he does not shoot threes and those he does he shoots poorly. His FT shooting is very poor for someone who gets fouled alot, and his 2 pt % is very pedestrian for someone who plays near the rim.

So to address the turnovers issue.
I son't believe I should as they are the end of a possession even worse than a missed shot, but, even if I exclude turnovers from everyone, KC moves up to 1.01 (points per possession except for TO), but that is still lowest on the team, and lowest of the starters by over 10% as everyone else jumps up too. Nick moves to 1.12, Fischer moves to 1.14, Davis is 1.12, Kaufusi is 1.22 etc etc.

So even excluding turnovers, it's troubling to have your primary offensive option be:
a) Turnover prone
b) Excluding turnovers be converting possessions at a 10% lower clip that the entire rest of the team.

Now - About assists.
The goal of this metric was to start with a team stat: How efficiently are they able to convert possessions into points - then extrapolate that to individual players.
An assist is not converting possessions to points - it is helping another player convert possessions to points. Many other actions fall into this same category and all are valuable.
What about the player who set the screen that freed the player
Or Held position on the weak side opening up the defense
Or got the steal that opened the fast break
Or the coach that called the play
Or the player that ran the backside cut disrupting the defensive switch
All of these actions are valuable which is why this is not a "value" metric - it's an efficiency metric. It only tells one story. How well did this player convert his possessions into points. Period. No more, no less.

The primary interpretation of this would be that those are not efficient at this metric should not be your primary offensive option. Since 2010, when BYU had a top three offensive option below a 0.9 efficiency they have not won a conference championship, a conference tourney, an NCAA tourney game, or been ranked. The 4 years prior to that - all of their top 3 scoring options had an efficiency over 0.9.

Second - counting assists is a "free" metric. As this is an efficiency metric, there needs to be a potential cost for the gain. For every opportunity to gain points via a shot or a FT, there is the cost of losing that possession. The assist is just free. Now - if the data was there, a semi-appropriate way to treat assists is to have baskets where it was assisted count as half for the player who made the basket, and half for the player who assisted, then you are splitting points, not manufacturing them. Then though, you get into questions about why not give a share to the screener, or the backside player, or the guy who split the double team, etc etc.

That's why this is not an "offensive value" metric. KC is hugely valuable offensively. The team broke when he wasn't in there enabling things. My only point with this analysis as stated many many times, is that for someone who converted possessions into points at a historically low rate, he shouldn't have been the number one possession consumer on the team. He forced too much - whether that was because he was asked to, or wanted to - the numbers don't care - they simply state that nobody on the team in recent history has ever converted their possessions into points at as low of a rate as he did.

I agree that if he wasn't playing, Nick, Chase, Davis, etc, would not have converted their possessions into points at as high a rate as they did, but that's where I wish he would have focused more. He consumed too many possessions at too low of a rate for this team to be consistently successful.