I endorse this post! With the exception of the following:
some folks take issue with you stating authoritatively whether somebody's idea is (not) cliche, or should (not) be attempted
That would be fine if he were actually correct in his feedback. I mean, for example, say, Echo hasn't written very much as of this post, but in certain areas his feedback (containment procedures, realism when it comes to military, practicality, etc) is invaluable.
But hey, we all start somewhere. Many of us gave a share of bad feedback up front. I have some pretty silly comments floating around in my comment history (I was especially heavy on the bad ideas, myself). But it's bad form to just keep doing it. So don't keep doing it, and all well be well in that territory.
Really your main issue, Dr Addams, is that you're taking this stuff much too seriously. That's making you try too hard and get too deflated when things don't go well. So… just take it less seriously. Keep writing, and odds are, you'll eventually get it. You don't seem like a horrible writer, so I'm sure you can come up with some good stuff.