Revelations of various kinds take place within a social context (time, place, etc.) Social contexts have changed over time, and I think the revelations have too.
Seeking a modern-day Jesus, Moses, Muhammad, Buddha, et al., is meaningless unless one extracts the essence of their revelations: that which translates out of their social context. Simply pulling these characters forward in time is meaningless. A precisely repeated revelation would not be a revelation the second time.
For me, the point is to extract this essence and strip away the happenstance, in a non-naïve way. Since it is this essence that matters, why couldn’t revelations come even from self-professed atheists? And why couldn’t there be a distribution of revelations of different ‘sizes’?