Agree, to an extent. The link certainly smells like an ad. If the predictions are on lower volume markets (i.e. no institutional investors with actual quants behind) the compounding power stops. Also that means it can't beat institutional investors. So the reasonable option is to monetize what you can.

He's been interested in forecasting since a long time before there was any money in it, and still hyped Metacalculus (free research project) and Manifold (play money) because he is interested in the subject. If it smells like an ad it is because your ad sense is faulty.