I was in IT for over 40 years, and remained a pretty much a generalist throughout.

I think overspecialisation has caused problems in our industry; probably a fairly high ratio of specialists to generalists makes sense when some small fields are very complex, but in general employers and recruiters take it too far with the sort of detrimental (and silly) effects mentioned by John Riley.

I think being just a DBA is something that would have driven me bats.