It's a person-to-person thing. Some people want or are open to criticism, others not so much. Some won't hear it from anyone but the GM, others want everyone to dump a container of nitpicks all over them. I personally think you should be open to criticism from everyone and anyone, as long as you're being reasonable about it. Throwing in curse words and personal attacks isn't going to help anyone, but if you word something strongly it should not be dismissed as the former.

I, personally, am open to criticism from everyone but don't get a lot of it. I'm not going to chalk this up to me being a great writer- I find issue with my own work all the damn time. I think people are either just afraid to give critique or just don't think to. Some can't even find faults with their own work, and so fail to find problems with the work of others.

If someone gives you critique, be open to it no matter who it's from. If someone is insulting you for 15 minutes long over an audio file... well, I think at that point they just hate you personally.