For many CTO/CISO it is more important to have a good target to shift responsibility when things go awry than to have a reliable/secure system. A Big Brand is a good target, an open-source project like OpenBSD is not. I doubt any CTO will be fired for choosing Widnows+CrowdStrike (instead of Linux/BSD) despite many million losses.
"Nobody ever gets fired for buying IBM" is as true as ever at least in the corporate world.