Coulter no doubt hopes the comment serves the only purpose she's interested in at the moment. Sell her new book.
That’s certainly a major aspect, but I do think she was also trying to point out the hypocrisy of the left by mimicking Maher.
Still, it was a dumb comment. She could have made that point in so many other ways that would have been more effective and less offensive. Leave wishing for the death of Americans to the left.