Yes, you are right...
we are to police ourselves. That is the only answer.
And you answered your own question: if the rules were changed to not allow a self upvote, the SCAMMERS would just open and fund a second account. Then they would use two accounts to vote back and forth. THis is actually a problem that has been done many times already. It is probably still being done. People do it to hide their greed.
But if we changed the rules, then it would be done much much worse.
The answer is us. The answer is you and me and the dolphins and whales and 1000 big minnows out there to stand up and say "STOP". And the way to say stop is with the FLAG function.
Thx