How is Grassley going to give assurances to whistleblowers within fed govt agencies? Agents want to be subpoenaed to get financial protection from retaliation from bosses. That can be arranged through citizens funding go Funds etc.
I think the crucial point is many fear for their lives and that of their family members. Think of all the people that bowed to Clinton machine over the decades. It's not only financial ruin these people fear.