Because he's a plant, and he's more effective for them as the ‘rogue’ Republican.
It was MCain who came charging back to Washington in the 2008 campaign to oppose TARP, only to turn around and support it. That was the watershed moment in the campaign and McCain sided with the establishment doomsayers and con-artists. His current statements are consistent with his past positions - the charade of conservatism, masking a core of RINO/Dem convictions. McCain’s motto is “talk loudly and poke a stick in the eye of conservatives”