Lets say that Cleveland does sign Hayward to a bid contract. If the Jazz don't match, and he becomes an All-Star level player, then they end up with egg on their face. Jazz had the chance to match for Wesley Matthews, but didn't because of the money. I know this is a larger scale, but Matching a max offer for Hayward is much less devastating to the Jazz right now than matching Matthews would have been at the time due to the current cap situation, and having so many players on their rookie contracts.
You don't pay a player the MAX because he MIGHT do something, said player should have already done something worthy of a MAX deal. If Hayward becomes an all-star (tough to do with Lebron, Wade, Carmelo around) the Jazz will survive. See Millsap as an example.