They are against economic retaliation for bidbot misuse, vote trading and selling.
They said it in their proposal.
They may be persuaded to remove free downvotes, but we already went through that and it sucked.
Minimum SP and rep, for downvoting, increased RC requirement, an an active post or comment would be good. I also think enabling captchas for comments (or increase RC to avoid) is another idea to reduce spam.