Hung, who is also the chief executive of the race's main sponsor Standard Chartered, believes critics of the race are a small minority and the majority of Hong Kong's citizens want the race to be a success.
He said: "Hong Kong people can dictate to a great extent the future of the path it takes. But there is growing recognition and a growing part of the population want it to be bigger and better. When application quotas [for 73,000 spots] are filled in three to four hours that sends a powerful message.
"This is something magical and I don't think people realise what an asset we have – or we collectively have – and whether we are leveraging it enough."
Hung added: "Hong Kong is a very vibrant can-do place, but we manage ourselves into becoming our biggest enemies sometimes by being negative, being critical.
"The marathon spirit is a unique blend that we should be leveraging because Hong Kong needs positivity."