I don't see what you think is different from a regular person buying steem to get attention versus an advertiser buying steem to get attention. Maybe you're arguing that the "regular person" is only doing it as a way to get additional rewards, whereas the advertiser isn't. While this could certainly be true, it certainly isn't necessarily so.
And in any event, both scenarios were considered in Steem's design.
When the advertisers buy themselves in it's contributive to the whole network. When a vote trader sells VP it's only contributive to that one vote trader. That's where I see the main difference.
When a minnow buys SBD to gain visibility it contributes positively to the network because it creates demand for SBD.The rise and popularity of bots lately is the reason SBD is pumping. I used to be like you @surfermarly I didn't like bots but my conclusion is that its a pretty good advertising model for steemit. The promoted tab doesn't work and advertisers are not going to lock their money to promote their stuff, so this is the best system so far. One thing though that's flawed is that 'advertisers' have a limit on how much SBD they can spend to promote their stuff, this is stupid considering that they increase payouts of everybody else when they buy SBD...