It was a modern alternative to standard wiring/switching which was to
revolutionize the electrical industry using space-age technology. In other
words, someone tried to create a better mousetrap but in the end, the tried and
true method won out.
Imagine not being able to replace a switch with a dimmer?
Also - the "system" was sold with other benefits and features, such as "master
control panels" where every switch relay could be wired to one or more "master
stations" where you could control 16-24 lights and see what is on and what is
off at a glance, as well as be able to push buttons which controlled assigned
"groups" of switches, or perfom assigned tasks (1-on, 2-3-4 off, 5 on, 6
unchanged, 7-8-9 on, 10-11 off) @ 7am... and vice versa at 10pm...