Moses gets away with it more because he's just a desk personality. He's basically there to compliment the more serious, tactically minded analysts. A part of his persona is to always believe in NA hope even when NA doesn't have a good team. When there isn't an NA team, he'll often pick the underdog.
Thorin meanwhile doesn't just take himself seriously as an analyst, he also presents himself as an esports historian. This makes his bias towards/against certain players very concerning because he can effectively re-write the history of CS:GO to suit his own fanboy narratives. Sure, stats will always be there to contradict him, but stats only reveal so much. 10 years from now, if Thorin maintains that Ex6tenz was a better IGL than FalleN, a lot of people will believe him.