OK, this team obviously has ill-fitted parts, the coach isn't helping, but you can't argue it.
This team has bad shooters, and the only good shooters are all dribblers, not catch and shoot guys. It's a nice talent, but there's only one ball.
Take a look back at the players you named, not only at their shooting %, but at how they shoot.
Outside of the all-stars and Conley (who is darn good), they are all low usage guys who happily stay out of the way and wait for their shoot. The closest thing this team has is Garcia, who is mediocre at everything else, is always hurt, and shot poorly last year.