Most executives are complete imbeciles when it comes to the actual work their organizations do.
They delegate and hire subordinates to do a job. It is by design that the communication won't involve 100% of the work done
You hire people to do a job, not to be a remote controlled puppet
But that want is limited (needs to be), and also it depends on the IC to explain things
I guess its impossible for an executive to know ALL the details of the work they delegate, but I'd be willing to wager that executives who understand the details function better in the long run.
It certainly isn't tautological that executives be imbeciles about the businesses they run.