Don't take all the feedback in the thread to heart. The fact of the matter is that even if you were more condescending than you desired to be, the joke in this thread about plumbers and pipes is also true. The end of the chain really does enter an absurd territory that narrows things down such that the recruiter was either failing very badly at understanding your emails, lying about his reason for rejecting you, or not even reading the emails. There is a very gross lack of comprehension in his later responses. It eclipses your condescension, by far. If it didn't, your post wouldn't be at the top of Hacker News.