That the writer says the things he does, is perfectly understandable; what is less clear to me is why a hope-to-be-credible publication publishes such obvious personal attacks -- unless the editor wishes he wrote it himself, and usually edits it for even more powerful offense.
Letters editors receive stuff like this everyday -- but they also receive well-written pieces also -- which they unfailingly suppress, thus giving thoughtful readers the impression that no intelligent person reads or writes for that paper. That has been a driving force in the explosive growth of the alternative, new media and publications of the Internet -- as people desperately search for intelligent life in the universe.
Every newsroom in this country is apparently presided over by some third-rate mediocrity who has been banished to "edit" letters from the deranged people who have developed obsessions and delusions of relevance and self-importance with the various letters editors seething in their own resentment and bitterness towards obviously successful people.
That should not ruin their day.