By being so direct, Ragnar took control of the flow of the conversation. The Earthlings had not planned on being so direct, as it was not the way of things. At least, it was not the way of things on Earth. First they had planned on conversing a little, and establishing the basis for a relationship.
Now, with the conversation moving directly to the topics of benefits, they had lesser room to manoeuvre the conversation. This was not mentioning the fact that, if what Slag said was true, there was hardly anything Earth could provide that the empire didn't already have access to.
Unlike when the Morrisons had negotiated with Chen and Lily, who did not have access to unlimited resources and were in great need of support, the empire probably did not need them to provide spirit stones or ores, or even weapons. So then the question came, what exactly could Earth do for such a giant?