I also feel that while angelwings is being negative and critical, (s)he isn't being vindictive. Part of accepting public opinions is the fact that not everyone agrees.
I've tried making my own games; I know how hard it is, especially to find a game others are willing to play. From my perspective, NGoM is a wonderful accomplishment. When I have problems, I make suggestions for improvement - this is my experience. If there's a problem, everyone tries to fix it.
Clearly, Angelwings is coming from a different background. Either it's your job to fix it, or your privilege (as it's your game), or (s)he is just venting and not expecting the problem to be fixed.
But if you only allow feedback that puts NGoM in a positive light, you'll only get good comments. I'd rather hear good things because the game is good, not because the dissenting voices had left for a more receptive forum. Everything has some room for improvement, I'd rather know where that room is than hear 'it's all great!'.
Sorry, I'm babbling. But my point is: Angelwings is Angelwings. I don't see where (s)he is being beligerent or abusive. Rude, negative, and overall gloomy - but I've seen nothing to suggest that kicking him/her from the forums is the correct response.