Examine the intent of the person who comments, if it is good, thank him happily for it. If it is bad, ignore him, that's best. If it is in doubt, give him the benefit of the doubt and thank him for it. You can choose to clarify, but there is no need to be defensive. Just keep in mind that no photograph in the world will please everyone.
At the same time, you are your best and worst critic. 8,000 people can comment, but if you don't train yourself to spot the mistakes you made, if you are not hard on yourself, it will amount to nothing.