Those who pay for delegations just to profit are gaming the system. The "spirit" of the platform, as explained by the original steem whitepaper, speaks of creating algorithms that would prevent gaming the system.

When buying SP, you're kind of expected to use it altruistically. It's not so YOU can earn more money, it's so you can GIVE more money, by voting on content that you deem valuable.

There's a big misunderstanding about the idea of "there are no rules here". Just because the system doesn't prevent one from doing something, doesn't make it any less rude.

And yes, self-upvoting by whales is a huge problem too, but that's not what this post is about.