Great information. I value your knowledge and research. I think you have made very valid points. Despite this, at the moment, I still like to list a few very relevant keywords. There are two reasons that I have found in my research that make me take the extra minute to write them.
Google crawls your entire webpage, and while I agree keywords are not used like keywords used to be, they still provide additional "content". I think that all meta tags and alt tags fit this bill.
Amazon, a giant everyone knows, uses keywords on their pages. Perhaps they have other in-house reasons, but there they are.
My two cents. Thanks for starting up the thread.