If you've got HP blade servers and call in with something even as mundane as a hard drive or mezzanine card failure, they will often insist you upgrade the firmware before agreeing "yes the hard drive is fuxxored" and sending the replacement part. Even more ridiculous is depending on the tech they might actually ask you to update the motherboard firmware when a motherboard has failed (Um, yeah.), or the iLO firmware even though it is totally unrelated to the problem (fortunately on HP iLO/LOM updates usually don't interrupt services).
The problem with that is even though you might be able to keep the services patched (and even kernel if you use ksplice) and measure uptime in years, updating motherboard or even NIC firmware requires downtime. Even an active/active cluster can introduce down time for some users so downtime of a server is best avoided. Why update the motherboard firmware if there are no bugs blocking production or introducing security issues?
I understand why support reps go through the script and ask you to update firmware so they're dealing with what matches their one test system in their lab, but if it worked as deployed for months or years with the older firmware until the HDD or card croaked, why require a firmware update to a known-stable system before agreeing "Yup, $foo has failed, I'll dispatch a rep with the FRU within four hours" even when S.M.A.R.T reports a hugeassed list of errors, or it's simply not even powering up?
As far as drive firmware goes, I've had to update firmware only twice: once on an SSD, and once on Seagate drives which would freeze during recalibration, which would break arrays (I think it was the infamous 1.5TB drives but it's been a while).