OP was talking about realtors. Realtors commission is based on final price, why not portraying the market hotter?

Because if you make the seller think the market is hotter than it is, then they price the house too high, and the house doesn't sell. That results in $0 commission.

I could see them telling buyers that the market is hotter than it is. But even that might backfire, if they make qualified buyers think that they can't afford to buy in the current market.

Okay, then presumably you can just appeal to the real basis for that claim, rather than the unreliable realtor source?