Apparently real and also quite traditional in second-hand book circles:
I’m on the same page as the ‘bookseller from hell’. Here’s why
His critics would argue that someone who is not really a people person should probably not be running a business that relies on interacting with people. But they misunderstand the nature of secondhand bookselling. Secondhand booksellers don’t like people. They like books. That’s the whole point. People who come in to secondhand bookshops – especially the ones who spend an hour sheltering from the rain, leaving puddles over the floor and making the cat wet when they stroke it – are bloody irritating.
The comments were largely on his side too, when I looked. I reckon it will be good for his business - although whether or not he appreciates that is a different matter...