The reason
Naturally, his words confused the businessmen. They were very good in the business world, had extensive experience, and had studied the geography of this city for a long time.
They knew perfectly well that this place was the best place to do business between the different races; which other place if not this one? And they had their own arguments to say so.
That's why they couldn't believe what Matt was saying, but still, they wanted to hear why he was saying it. They wanted to understand why Gray Allen chose him as Leader. And if they could, they wanted to make him wrong and then bombard him with valid arguments as to why this place is so good for business.
So they talked.