The concentrated vote implies less effort finding hidden gems
@clayop voting for "more authors" does not necessarily mean doing the best job of curation, nor does it imply "more effort". I'm accusing no one of anything but one could easy create an army of sock puppets and vote for each of their posts, creating an appearance of "voting for many different authors", but it would all be fake and self-serving. Perhaps slightly less sinister but also useless, one could simply browse New and vote on any random crap posts, producing a small-but-consistent reward with minimal effort and in doing so also vote up a large number of different authors.
I'm happy that the authors I've consistently supported have produced content that gets votes from other community members, sparks engaged conversations in the comment sections, and is downvoted rarely. I've also voted on a good number hidden gems that then went on to get many other votes after I discovered them. Those are the primary metrics I use, along with my subjective view on what is adding value to the platform and generally helping it to thrive in various ways.