The intital hbdstabilizer budget was 100 HBD per hour from the DAO, or about $2400 per day. Seeing both quantifiable and subjective success with that budget (as well as all of the funds being returned, plus profit), stakeholders have repeatedly voted to increase the budget.
RE: The main excuse for malicious down-voting is "Over-Rewarded Content..." What about the account making $10k+ PER DAY in spam comments?