I agree with this idea, and do not see a reason for which it shouldn't be implemented. This should, at least, be implemented for ICO's (although this would make it somewhat difficult, but it would still work).
It won't stop them. Let's say there is a project made to scam others then in order for them to post it here then they pay 1 bitcoin then proceed.
If it "won't stop them", then there is no reason not to add this. They'd at least be down 1 BTC for even attempting to run a *scam* and this would turn away the [insertWord]Coin spam.