@paulag This is not true. There is no such rule nor consensus on self voting and I've been on Steemit since day 1. The whole trending page has always been full of selfvotes and still is. That's the whole point of steem power and the attention economy. To give your posts more attention and send them higher or even reward yourself if you put in the effort. It is not just a curation game. If the rewards are considered too high then someone else may come to downvote, but noone contests the self vote itself for genuine posts that took time to make.
Self votes are always considered okay unless for spammy or low effort comments (Ned in a video even said he would like to see more people competing for attention as that would drive up the price of Steem).
but the case you presented in this post is indeed one of those cases that needs flagging as they are low effort spammy comments