Well, you're wrong, at least for a specific segment of hardware and software on the market. The size of a packet is not related to the acceptable per-connection overhead. Some network devices like ASIC-accelerated routers can't handle any per-connection state.

If you don't believe me, hop on any kernel development mailing list and try to convince them they could solve world hunger by only adding 1 KB overhead to the TCP socket structure that tracks actve connection states.