That's an interesting question.
I believe that bots can have their place on Steemit and can be useful for promoting content. This could help build the platform especially if bot upvotes can encourage advertisers. As I mentioned in the post, content creators could include advertisement banners in their posts.
Having a very large share of bot promoted content that is low quality on the front page (trending) is bad for Steemit's image. This will put off content creators and investors joining the platform. Someone who is heavily invested in Steem should care about the long-run price of Steem more than accumulating more Steem. Also investing in Steem purely to delegate to bots is not a great financial move. All that is happening is that bot income is compensating for the inflationary nature of Steem. This type of investor could invest in another cryptocurrency that has a lower rate of inflation. The true and unique value from investing in Steem is the social media element.