That’s some awesome anecdotal evidence. I’m entirely willing to think that people will upload a submission and downvote everyone else’s. I don’t recall hearing of a preponderance of cases where they upvote one single submission and downvote all others, with the possible exception of the Bashy Bashing fora. Admittedly, I’m new.
In other words, it’s not that I don’t believe the behaviour exists, it’s the “most people” to which I object. Although I also don’t know of any reason why someone with five alts should get 5 times the upvotes, even given the elimination of downvoting.
It’s one vote per submission per registered account, not per alt.