How can one respond to the specious argument regarding the scarcity of authentic hadiths in "Sahih al-Bukhari"?

Imam al-Bukhari was a formidable and sagacious memorizer (hafiz), acknowledged as such by his contemporaries and those who came after them. He was tested in his memorization and passed the test with remarkable success. His statement, "I memorize one hundred thousand authentic hadiths and two hundred thousand inauthentic hadiths," does not imply a scarcity in his memorization of the authentic. Rather, it means that the inauthentic (including the hasan and da'if) are greater in number, and that by "authentic" in his statement, he means what reached the highest degrees of authenticity. Al-Bukhari left many authentic hadiths that he did not record in his Sahih.