I think his opinion is just that Bitcoin is not yet fully become legal to a country and other countries, he says there is no stopping criminals to join mining bitcoin? Helloooo!!! Are all small business on the street legal either? (I don't discriminate sidewalk vendors since I like street foods), some of them don't have permits like sanitation, but government allowed it since its one way to help people help themselves; and all people who plant marijuana on the hidden island or mountain have permit to operate either? Since it helps also non criminals to earn money by just planting, if you get what I says, and it's not legal also, so whats the different from bitcoin?
That's why step by step, government will implements some laws on Bitcoin for them to fully accept its existence.
bitcoin doesnt need laws to scare off illicit 'cryptomining'.... ASICS done that for us.
its not rational or profitable to CPU/GPU mine any more and so hackers simply do not bother making apps to illecitly cryptomine bitcoin.
all that needs to be done is for the altcoins to not resist ASICS but to develop mining tools that dont require PC software to mine, then its not a problem