Why couldn't you just trade with registered and regulated companies with high liquidity?
It sounds unappealing, I understand, but why couldn't you?
In addition, it's good that you can count and record the amount of "scams" which has been committed using bitcoin, could/would you like to compare that to fiat?
Registered company means nothing, You can start up a company in the UK now using Bitcoin and Anonymous names. SSL certs can be issues to these companies cheap.. It can look like a legit service but still be a scam.
Fiat is incomparable to Bitcoin right now IMO, It is globally adopted and of course there are going to be more scams, But really on percentage I imagine Bitcoin has a larger percentage per non-scam user to scam user.