I'm a bit of a writer, I don't know if I'm any good. I do some multimedia stuff as well since I'm not too good at hand drawn or digital art type stuff.
I always believed in constructive criticism and feedback on works because it lets a writer know how good or bad their work is. I for one welcome all forms of constructive criticism, even the bad ones because it helps one improve and learn from their mistakes.
However I utterly loath absolute silence, the people that say nothing because they want to “Spare” your feelings and I hate people that coddle me or others like that because they are worried bad feedback might upset us or whatever. Silence is the worst thing to do because then you don't know for shit if your works are good or bad and therefore have no grounds to improve them because you lack direction.
Seriously if you have friends that are artists, writers or just do anything creative then please give them feedback on their works, even if it's bad feedback, just please offer it because we welcome it. It helps us sharpen ourselves and our crafts so we can better ourselves.