Critical Reasoning (CR) | In any field, experience is required for a proficient person to become

This is what the last sentence says:
Although computers have the ability to store millions of bits of information, the knowledge of human experts is not stored within their brains in the form of rules and facts.

So they have the ability to store a lot of data but they do not store the knowledge of human experts in the form of rules and facts (apparently the form that helps humans take intuitive decision about new situations based on experience)

By saying that "computerized “expert systems” cannot be as good as human experts," we are assuming that the knowledge of human experts cannot, in the future also, store the knowledge of human experts i.e. we cannot convert the "knowledge of human experts" into a form that the computers can store (and usesubsequently).