I think you mean the bitcoin/cryptocurrency market manipulation, am I right? Because I don't see any problem other than that.
He claimed that this specific set of people is seriously impeding the adoption of Bitcoin. As they have the ability to shock the entire system with sell/buy.
If you mean whales, I believe that a
"specific set of people" or whales don't control the price completely. The price goes up and down because there are speculators and the panic guy. It also happens in the forex market, right? So that's not a problem.
I believe the system should be changed such that each person is limited to holding a certain quantity of Bitcoin.
The Bitcoin supply total is 21 million; if the system limits the amount of holdings, what is the maximum value you want to propose? Do you want to implement a communist economic system into Bitcoin? Sounds centralized, doesn't it?