The cross-fertilization of ideas across computer science domains is more limited than I think people assume. Databases are just one area that contains a lot of good ideas that never seem to leak into other parts of the software world.

Supercomputing is another domain that has deep insights into scalable systems that is famously so insular that ideas rarely cross over into mainstream scalable systems. My detour through supercomputing probably added as much to my database design knowledge as anything I actually did in databases.