So, the way the writer puts it is that Koreans were inherently talented, and their willingness to accept Christianity in such numbers further proved their quality as a people. (My understanding is that the writer had spent some time in China, either as a missionary or as a traveller, but I have no info on whether he visited Korea.)

“As I looked upon those lighted faces, wearing an expression strongly contrasting with the dull, dazed look of apathy which is characteristic of the Korean, it was impossible not to recognize that it was the teaching of the Apostolic doctrines of sin, judgment to come, and divine love which had brought about such results…” (Bishop 342)

Especially during the Japanese-Russian war one could read often in the newspapers about the laziness and stupidity of Koreans and how they are indifferent to the fate of their country and people. But those who have spent a long time among them tell otherwise. In general they are lauded as diligent, willing to learn, modest, sturdy, and calm. [...]
It has been also told that two years ago in a student’s world conference in Tokyo a Korean student made the most brilliant speech. All of them are for sure not this kind of geniuses, but because of the few who have been in contact with the Westerners such examples could have been picked, there is no reason to believe that they are exceptions. (Translation AL)

From the booklet Herran hengen töitä Koreassa (Works of the spirit of the Lord in Korea), Finnish Missionary Society 1910. Originally a presentation given in the annual banquet of the Society in 1909.

Perhaps some of the admiration towards Koreans in this fascinating little booklet stems from the receptive attitude of Koreans towards missionary work (which the writer talks about at length), but there must be some politics as well since the Japanese are presented in a very bad light (“oppression second only to the king Leopold’s government in Congo”).