Remember also that by his 'turning' it weakened the moral of others. and helped to create other cooperators. Especially back in the mid-1980s when becoming a rat was a rarity by comparison to today.
The FBI loved every minute of it. They used him to say.... "See what Michael did"
He helped to open the floodgates for them. His words and actions were used to convince others to do the same (or face the consequences). They used what he told them to scare others with that new found knowledge.
Similar to what DiLeonardo and Gravano did a few years later. And as well. But he was one of the first.
I agree with you on that point. He did.
