Looking over the stats of some of the "consistently great contributors", and mapping that against the "most followers" list… I'd say that it happens a lot – if you include "celebrity" as a job title, or expand scope to include "general notoriety" across many other axes.
In part, it's just more likely that someone with a high degree of recognizability will be able to provide amazing personal insights within a set of focused topics… But it's also true that those rare times (for most) that they stray into topics they are not well known for, the novelty of their answer (even if it isn't that great) again makes the follow worth it.
That said, if your goal is to fill your feed streams on Quora with great quality content, then there does not seem to be as clear a correlation between that goal, and following people based on an external criteria like job title (apologies to the many edge cases – but for every great Facebooker or Hollywood screenwriter contrib, there are quite a few more with shinier-sounding jobs who either lurk, flail, or abandoned their accounts).
