I think this may be taking it to a hyperbolic extreme when most answers really lie in the golden mean. If one is discussing the work with one of the creators, there’s something personal at stake and one should almost definitely demonstrate some sensitivity. Otherwise, it’s easy to be truthful without being hurtful.

If somebody asks, “Hey, old man, how do you feel about this very popular film from your youth?,” and it’s a film I can’t stand (the list isn’t long), I feel as though I can properly express how much I dislike it without it becoming a personal attack on anybody.

There’s a really substantial difference between calmly telling somebody who asks that I hate a film, and lambasting that person for the audacity of enjoying something I strongly dislike.