Who was manipulated when the reward formula was changed? Were you manipulated into not mining and buying early on because you thought the formula would remain the same and it would for some reason be better for you to buy or mine later on? And then when the formula was changed, and people voted for it by downloading the new client, that was the moment when you got scammed and manipulated?

When a coin is still new (as it was just a couple of months old), that's the time when you can still make changes to the parameters of the coin if deemed necessary to prevent a problem imo.

If we would adopt your puristic view, all coin's features would have to be carved in stone at the launch. If later on you come up with a new feature or a service for the coin that will be very valuable and increase the price, there would be people screaming manipulation and scam because adding value to the coin would unfairly benefit those who were early and got their coins cheaper.