I think the definition of "systems" changed over time. It used to mean building the foundations of operating systems, e.g. kernel and basic userland utilities.

I think the definition of "systems" changed over time. It used to mean building the foundations of operating systems, e.g. kernel and basic userland utilities. Now it means building higher-level userland tools and internet oriented tools. I think the implicit consensus is the lower level stuff is a "solved problem".