I'm going to be more scathing and say this property has nothing but contempt for Diamonds. An Australian based Frequent Flyer group actually refer to anyone staying at the Hilton as having Stockholm Syndrome because no-one, including those with lengthy stay history, receives a suite without fighting with front desk or involving the Diamond Line.
Of course they do sell suites, but the reality is they do not seem to upgrade Diamonds, even on higher room types to suites.