>> They provide as much of a sanity check for enterprise/commercial IT decision making as a customer desires.

Exactly.

No-one gets fired for buying the vendor in the top-right corner of a Gartner matrix...

I'm also amused by vendors (often start-ups) releasing PRs about being listed in a Gartner Hype Cycle report. "Look we're here, at the top!". i.e. overhyped...