compilers and related research was at the forefront of technology itself
Excellent point dude. Computer science as a means to profit has become the application of computer technology to specific domains: financial securities trading, automobile ignition systems, sound engineering, microwave oven design, defense systems. Why specialize in a tool you can hire somebody to use for you, when you can specialize in the domain itself?
The change happened when computers got enabled as feasible tools. While there's still progress to be made, CS itself has lost the limelight, and things will probably stay that way until a paradigm shift fundamentally alters the field, maybe say when computers are no longer Turing machines.