The problem isn't the odds and who wins the lottery, it's that they only lottery off the top three picks. Having the worst record doesn't come close to guaranteeing you the first pick but it does guarantee you at least the 4th pick. which balances the risk/reward of tanking, especially when there is a deep draft. If they raffled off all the picks then there would be no reason to change anything. You would just have to teach teams to understand odds.
And I agree with Cleveland, if they do make changes, they can't do it for next season, they have to give teams a warning. It's not fair to suddenly make a change.