There is a difference between responsible criticism that aims for success and defeatism that refuses to acknowledge anything but failure. Hindsight alone is not wisdom, and second-guessing is not a strategy.
I wouldn't be worth my salt if I weren't attracting some controversy and criticism. Everyone in the world who has done something in life has attracted criticism.
An artist must only judge of what he understands, his field is just as limited as that of any other specialist... That in his sphere there are no questions, but only answers, can only be maintained by those who have never written and have had no experience of thinking in images.
The sceptic will say, 'It may well be true that this system of equations is reasonable from a logical standpoint, but this does not prove that it corresponds to nature.' You are right, dear sceptic. Experience alone can decide on truth.