Operating old Mainframes was RE: Collection policy

The aim of a business is to make money - and most would agree that homo-sapiens is essentially a lazy creature (at least, I am)! In terms of hardware and software design and production, this means more and more layers of abstraction between the basic computational structures and the functions that users desire. Doesn't it seem like a natural progression then, that not only do fewer and fewer people understand less and less about machine and system architecture, but given sufficient time, the nature of the IO devices and operations has/is becoming so different from the earliest systems, that it is becoming a non-trivial task to understand even their function, let alone their correct modus operandi (e.g. how many hardware engineers today would recognise, let alone understand the detail in the design of a mercury delay line)?