The economics have changed since the last hardfork and it's no longer as expensive fighting abusive voting behavior.
I don't believe a vote buying system that pays people to advertise is in the best interests of this platform. People who profited from buying votes in the past unchallenged now run the risk of getting burned, and in doing so should think twice about purchasing votes in the future.
RE: My HF21 after thoughts and impressions of new steem trending page