I think that when anyone puts a piece of art out there for the world to see, they should be aware that not everyone is going to enjoy it. Artists shouldn't be immune to criticism. Just take a look at all the people that think LP's music is terrible. The band doesn't care, they just keep on making music that they enjoy. My point in expressing my opinion of this persons art was to do just that, express an opinion, not to potentially damage their personality or anything else.
And as a disclaimer: I didn't take part in this contest. I have no artistic skill.