Sabathia is going to get in. He won the Cy Young and finished in the Top 5 on four other occasions. He was a good postseason pitcher who pitched extremely well in 2009 when he won the World Series. There was a time in his mid-30s where his velocity dipped down and he had some personal problems and it looked like his career was going to be over, but he bounced back and was able to string together several solid seasons that allowed him to clear some critical milestones, including 250 career wins and 3,000 strikeouts.
The case against Sabathia was that he was never particularly dominant outside of that half-season in Milwaukee, which is why his WAR is fairly low (62 career bWAR) despite a very lengthy career. He never led the league in ERA, ERA+, FIP, WHIP or strikeouts. In black ink he falls well below the Hall of Fame standard, in gray ink he is slightly below average. To compare him to Grienke, who has 73 career bWAR in more than 500 fewer career innings, it shows how great Greinke has truly been