"Given how good this product is, there is little doubt that it would have sold well even without advertising" ... if this reasoning held true, the advertising industry would not be worth hundreds of billions of dollars, wouldn't you say ?
But ok, steem is a lot less crowded by good content than the markets are crowded by good products so perhaps you are right in the case of steem, I'll try as well.
However what you are implying is that because bot-usage can be abused it means all bot-advertising is bad and should be fought.
Think about it: because some people abuse bots, all bot usage is bad ? Does that sound ok to you ?