In general, I agree that a comment usually means more than a vote.
But that's not really the question here - the question here is whether restricting voting because some people vote 'too much' is in any way a reasonable point of view for an instance on the Threadiverse. As Rimu himself pointed out, the primary targets of this are ten 'top' voters, who are hardly going to be placing more comments to 'replace' their lost votes.
Assuming, of course, comments aren't next to be limited, since that's also an 'outsized influence' from a 'small minority'.