Cruz is merely there to ensure a contested convention, and for any of his supporters to state otherwise is pure delusion.
Trump needs 1237 to secure the nomination, if he can't get there it goes to an open convention. Those are the rules, we have to live with them.
Are we just supposed to ignore the rules because the Trump supporters don't like them? If that's the case, Trump should just be given the Presidency. Why bother with that pesky general election?