Many will criticise him, because it's him that said it, the classic ad hominem. 'How dare Charles involve himself in such weighty matters? He should stick to polo' etc. Bollocks. If the man speaks the truth, judge him by that, not who he is.
Then there are others who wish to push the GM agenda, either their paid-for shills, or the ignorant. Genetic modification is inherently dangerous, and the evidence is legion. Some of it is freely available in the documentary below. It cannot be contained, therefore GM crops spread contamination widely. No farmer or land-owner has the right to contaminate other people's land. The company leading the GM movement is one of the most demonstrably evil corporations in the world - Monsanto, the ultimate monopoly capitalist nightmare, which literally wants to control every seed planted in the world.
So well done Charles, for speaking the truth, and fuck all those that attack you for doing so.