His comment is not true. As I've already stated I emailed only those who I thought would respond to my concerns. I never expected to receive an email from David directly.
You bypassed their provided means for customer service and sent a presumptuous email. Sorry, that entitles you to nothing, even if you are a paying customer (unless direct developer support was part of anything you purchased). Don't crash the party expecting to be welcomed with open arms, or even gently escorted out. Karp could have used more tact, but as far as etiquette goes, he was totally in-line with responding to your message how he did.