Wait, you're not supposed to receive (constructive) criticism if you produce work that is sub-par?
Honestly, there is a lot of potential behind an idea, and I hate to see it completely go to waste like this. Just the description already sounds half-assed. The idea behind Nebula combat training is a good - in fact, the GTVA would likely have a simulator module for this just in case they ever needed to send fighters into any nebula again. However, fighting 1000 waves of 6 Maras is not combat training.
Sure, you can make a mission like this to practice set up in FRED, but you shouldn't post it without expecting some sort of comment on how you could improve, or what could have been done. Imagine how polluted this board would be if everyone posted their "Fight a wave of fighters" mission that they made when they just started out - you wouldn't be able to find the good stuff under the massive volume of, essentially, crap that everyone else has probably done before, but was smart enough to keep it to themselves as a learning experience and not try to show it off. I'm not saying the James should stop FREDding, I'm saying that he should keep working hard, and release something better.
What is expected here by most people is not some 'I'm learning' mission thrown together in twenty minutes. I believe that people here expect a somewhat finished product which at least has some depth to it. If you can't put together something like that yet, then keep it to yourself. If you need help, there's the FRED discussion board for that. There's no need to show the community every little thing you do as you improve, because most people don't have time for that.
Sure, we all could have done with a little less 'edge' to our words, but that would lessen the effect, and I've found that subtlety often gets ignored, or misinterpreted. Hence why I'm usually blunt.
TL;DR Version:
I think that this behavior is tolerable in this case, as long as it remains constructive, and isn't overly rude.