Sean Knight looked at these people and found them to be rather ordinary.
They didn't have the impressive qualities that some Europeans claimed foreigners would possess.
Seeing others make money, they would become envious. Acting under the guise of others' best interests, they would resort to despicable deeds.
In fact, he didn't really mind letting these people in. Sean was pretty sure that there wasn't much more to find in the passage.
However, it was he who discovered the passage. If they asked him softly, he might actually let them in to have a look and try to reap some benefits.
But now, with this forceful approach, Sean didn't like it.
Since he didn't like it, he wouldn't let them in.
I'm gonna monopolize it!
He just watched as Eiris Perez stopped those people.
If Eiris Perez couldn't stop them, Sean didn't mind using force to let these people experience the "Kung Fu" of China.