the criticism is largely unfounded
Not so.
My criticism is that he gave me crappy pre-sales support (which resulted in me not becoming a customer of his).
That is perfectly well founded...he gave me crappy pre-sales support, and you'd have to have a rather vivid imagination to construe it any other way.
It is my belief that you either are a good seller or a bad seller, this nonsense of 5 star ratings on eBay is...nonsense. It's either 1 or 0. If you fail at something as significant as customer service and make no effort to right it then you've got yourself a 0 for the whole shebang in my book.
Again, I did not intend for this to become a 'big thing', so I'm done in this thread. The blame for this topic going beyond a single post does not fall on me - I made a single post and expected, at least hoped, it would stay at that.