The point is that you implied that an individual should not be disrespected for their personal choice.
However, Thoreau was a public figure and influential so according to your standard one should therefore be allowed to view him negatively (which I do).
Thoreau took the consequences of his choices (which were not injurious to anyone). There is no reason to view him negatively unless you’re projecting on him how his followers have acted after his death. It’s the Nietzsche effect...an honorable man who’s had the misfortune of dim followers.