That's a strange definition of lose. A third party doesn't contract with someone for their product launch, and that is considered a loss of money?
So as i read it, the argument being made is: if Google had chosen the same path as apple did in their app store, Google would not have missed this opportunity.
Allowing people to get apps that don't need these services elsewhere is also a good idea.
What percentage would not be extortion to you?
Why that percentage? What are the costs for all the services these storefronts provide?