1. Discuss and criticise, don't flame. Attacking somebody for merely holding a different opinion only shows others that you aren't capable of engaging in reasonable debate. If you disagree with or dislike what somebody says or shows, state why.
2. This section/forum should not be used for short five-word protests in the vein of "I hate anime" or "Digital Art Isn't Art". You should give answers like "I like the source of light you have put in the down left corner but i don't like very much the c4d you have used. I think the render should be in the centre and not in the left." Express yourself fully and understandably.
3. You should never make fool of (or offend) someone because you don't like his work... He could be a begginer and he may not know things a more expertised person or you should know. Explain him what he should add, remove or show him a technique to improve his art.