I'm not sure when those days were. Maybe the 1980s? In the 1990s VC firms I interacted with were made up of partners whose background was non-tech and associates who were freshly minted MBAs. (Who had lots of opinions about what we should be doing which seemed to be totally buzzword driven.)
Certainly not the 1980s. John Doerr was rising then, and his operational background isn't much. Art Patterson at Accel was a big early hitter in software, and he'd never operated much. Hummer Winblad was one of the more successful startup VC in the 1980s, because of their software focus; Ann Winblad had started a company (and sold it pretty quickly), but John Hummer went straight from his sports career into the finance sector.
Even before the ones I named, Don Lucas was first guy in at Oracle; I don't think he operated much. Ditto Jacqui Morby and Henry McCance in Boston.
And Ben Rosen was a stock analyst, who trained the guy who trained me. He was one of the best VC of all, although he didn't bother doing it for long.
My anecdotal evidence is that VC is more a "operator turned VC" now than ever before. VC used to be all MBAs / finance types (e.g., head of tech research at an investment bank). But every year, it is harder and harder to become a VC partner without significant operating experience. I am not sure who has hard stats on this though.
