He had some pretty progressive views on treating addiction based on his own experience with it. Also he was my favorite on the show even though the show is undeniably problematic in many ways, it still brought me comfort to come home and watch it after facing bigotry back in high school, kind of an escapism into a reality where I could be an adult with friends.
All in all I am mildly shocked and bummed, but it's hard to merit much dismay about the death of a wealthy actor when I'm already much more concerned about oppressed Palestinians.