No, I am not making his point for him. You are convoluting arguments. The entire thread is predicated on point differential that was calculated with our best, and most important player playing. When you take that out of the equation it's a completely different discussion. The discussion is then something like how good are the Kings without Cousins, I assume you can see how that is something much different than point differential as a predictive measurement.
Cousins has missed an average of 12-13 games per season (due to injuries, rest and suspensions)and the Kings have an awful record in those 60+ games over that span. It's definitely part of the why they've failed to make the playoffs. But while taking away the games Boogie misses when looking at the stats puts a much better shine on things it doesn't change the end result.
And Brick's analysis wasn't that teams with a positive point differential only when their best player(s) are playing make the playoffs. It was that teams with a positive point differential over all 82 games do.
Those 82 games will include some that Cousins misses. Those games count in the statiatics too regardless of why Boogie misses them or how dependent the team is on him.