Win shares especially defensive.
He's playing for a bad team, of course that's low. His offensive win shares are middle of the road but his defensive w/s are his 2nd lowest number he's had. Total win share's this year rank 7th of his 9 seasons played. You are looking for a reason to bash him when you resort to quoting defensive win shares and ignoring every other statistical category. Especially when you're only comparing that number to his previous seasons instead of doing so against other players in the league or even his own teammates, where he's 4th on the team.
Saric is 3rd on the team in defensive win shares this year, does that mean he's a good defender? He's 3rd behind Oubre and Bridges, just 0.1 below Bridges though. Rubio is 4th. Oubre leads with 1.2, Bridges 0.9, Saric 0.8, and Rubio 0.7. How much do those stats really tell you?
Again, he's posting career bests in a number of categories like PER, eFG%, assists per game, turnovers, assist to turnover ratio, and points per game. All numbers he can control more on his own rather than statistical measurements that are heavily influenced by being on abad defensive team as a whole.