in my view this is good for the Crypto-currency world. Most scam projects coming by advertisements , so the people caught . after the ban definitely the users willing to go Ranked websites. As an example if you want to invest ICO , definitely now you check with a Ranked websites like ICO bench , ICO drops etc.
NOw filtered the scams, anyway this is good action. this ban means they indirectly supporting the Crypto currency future
You are absolutely right. Google and FB ads made scam coins make easy money. this decision by both companies is good.