Can't disagree with any of that.
One thing I would like to add, hopefully without detracting from your points, is that most of the contributors here are not professional photographers. Most (I imagine) are amateurs and are not going out with expensive DSLR type cameras, but point-and-shoot compacts. The high quality images taken by the serious photographers are always very welcome and very inspiring, but isn't TMA about getting out there and sharing information, knowledge and experiences? Images on here should be telling us something about the site, or its setting (as yours undoubtedly do Robert), rather than about the camera they were taken on.
To my (very amateur, very enthusiast) mind, there are lots of great images on TMA taken with lesser equipment, some of the grainy old scans and early digital images posted in the site's formative years are just as evocative and informative as those taken by a pro or semi-pro with the best equipment.
There is an element of the tone of this thread that suggests TMA should raise its submission bar to be a collection of pictures worthy of entering into competitions, to be judged purely on questions of exposure, or shutter speeds. If this is the case, a lot of enthusiastic but amateur contributors probably wouldn't have the confidence to post pictures here any longer, and I reckon we'd lose more than we gained as a result. I'd like to think that TMA is a broad enough church to accommodate both the fine art and the enthusiast who wants to "show and tell". It's all about the sites, after all.