I'm not even talking about his policy positions. The Republican establishment HATES him, and not just because he's a "maverick." He's pulled stupid stunts with no hope of success that have caused the entire party to look bad. Regardless of how successful you believe the Tea Party has been in the past decade, you still need your party's elites to at least be able to stomach your presence to win a presidential election.
A bit like the Gipper who was loved by the establishment politicians before he rose to power?
All kidding aside, I do acknowledge your point and Cruz has been making quite a lot of enemies during the past few years.