I appreciate what you're saying, I really do, but I think most people who search for something look at the title and description in the results, I don't think they'd spend too much time analysing the quality of the domain, how many words it has, or whether its a .co.uk, etc.
I think they'd search for something, and click on the results that seem to give them what they want.
In my mind if you have good quality domains to sell, what better to do than put them on a domain that could quite easily get itself right under the noses of the people looking to buy them.
There's nothing to stop people having 20 websites all selling the same stuff, but aimed at different keywords to get the maximum exposure possible, in which case this could be a useful addition to the armoury.
But I do agree about it appealing mainly to domainers and them being a tight bunch
