I think we are confusing terms. I don't mind that you think it sucks, IF you have a reason. Then I might disagree or agree with that reason. What you are describing is something totally different. I let people read my writing: Some said it sucked and others loved it and and they've always had their own reasons why. BOTH are criticism and I respect all the opinions I recieve because they told me why. If someone told me it sucked and their reason was "just because", that opinion is totally worthless because I have no information to work from.
Like the guy you describe commenting about your film. It could have been anything. Jealousy, for one, because you have finished your feature and he/she hasn't. You came up with the funds/time, and everything else you needed to to finish it. They haven't. So what they were offering wasnt criticism. It was just negativity.
THEN, MY FRIEND, YOUR ARE OFF-TOPIC TO THIS DISCUSSION ON A NEED TO ENCOURAGE PEOPLE NOT TO GIVE UP AND SUPPORT THEM IF THEY TAKE A SHOT AT TRYING TO MAKE ANOTHER FILM RATHER THAN MAKE SOME SORT OF REFERENCE THEY CANNOT GET BETTER. PEOPLE NEED HOPE THEY CAN GET BETTER.