This is not true. In order to do what ITA does, you need schedules, fares, and availability data. You can buy the first two from clearinghouses if you have enough money. But the only way to get availability data is to either contract with airlines directly OR contract with your competitors.
I am sure that there are still some old LISPers around that can write a similar software for a new company.
That is just breathtakingly wrong.