I never mind someone making constructive criticism or suggestions. Kudos are always welcome, but we cannot always be spot on in every shot we take.
I will admit that I used to be on the side of ruffling feathers. This can come in 2 ways, intentionally trying to be argumentative or unintentional. Again, in my youth and arrogance, guilty of both.
Now, being older, wise and having a more compassionate heart, I do my best to try and provide any feedback to images in a positive spirit and hope it is taken that way.
I may not appreciate the subject matter, the composition or the processing....and if I see no way of providing a positive feedback - I just don't respond. However, if I feel that there is a way that could make the contribution to the conversation, I need to ensure that I state the critiques in a positive manner.
I'm not going to say, your composition sucks, the processing makes my eyes bleed or I hate the subject matter because it doesn't agree with my moral fiber. I take photography like art. I may not appreciate it or understand it, but I respect the right of someone to create it, show it.
We can discuss and disagree, but we should never get to the point of hate or anger or personal attacks. Once you've gotten there, nothing positive can come from the discourse.
Don't get me wrong...I'm human and sometimes I fail at what I just stated above. It is the goal I go into the conversation with, though.
I think the vast majority do something similar. I don't think that we always consciously want conflict, even those that seem to specialize in it.
A quick story: Shortly after my wife and I were married, I noticed a pattern of behavior in her that was a bit troubling. Roughly every 3-4 months, she would try and pick fights with me. After 3 or 4 of these, I had to sit her down and find out the root cause. After many discussions over a few months, she realized that having come from a dysfunctional and abusive childhood, she was used to and thought normal to have your world turned upside down every few months. Unknowingly, she was uncomfortable in the fact that we were not fighting...so she tried to make her life with me "normal".
From my view, people that want to tear down others, pick fights are doing so for a reason. Could be similar to what my wife was going through, could be that they were/are being bullied and they think this is a good way to try and regain some kind of power - by bullying others.
We cannot control other people, only control we have is how we choose to respond. We can fuel the fire, we can ignore, or we can take the high ground to engage and douse the flames. If that is a struggle for you, may I recommend reading the book Boundaries by Henry Cloud and John Townsend. It is a pivotal book in helping my wife overcome and re-write how she lives her life. No longer being guided by the old rules of her life created through dysfunction.