"The issue is no one knows what it will produce. The community will be able to submit these proposals."

You're ignoring his point. The funding for the SPS proposals is coming only from content creators, who currently share ~10% of rewards now. ~90% of the benefits of any SPS proposals are then delivered to non-creators - who didn't pay anything to fund them under this proposal.

That's his point. The funding is extracted from content creators whose median payout is .01 SBD now, and a 10% tax on creators is going to reduce that, leaving even less incentive to create content.