What I don't get is what's so subversive/ironic about any of this. What part of this seemingly-polite note can't be, or shouldn't be, taken at face value? He doesn't think the investment is a good fit right now but agrees that the company is worth keeping an eye on, and is appreciative that YC took the time to think of him.

Not a business for introverts or borderline aspies like myself, I guess...