When the WTF took the ball and ran with it, they made one touch down after the other. Right now, it's at about 200 (Nations in the WTF) and counting. I don't think the Kukkiwon could quite keep up with the explosive growth the WTF created. I think it surprised all the seniors.
What has happened is that for decades Taekwondo has grown rapidly in many nations, and in those nations the original Korean instructors met together and made common, but somewhat loose rules like 4th Dan is instructor, and maybe that means master, etc. Because back home in Korea, no one could take the Sabum exam until they held 4th Dan, and, graduated the Sabum course. There was no course available to non-Koreans during that time, until 1998. So all these people thought they were automatically instructors, or masters at 4th Dan, or 5th.
Those of us who started attending those first years of courses started coming back to our countries and sharing the information we learned in Korea. And some of that information did not match with what had been going on at home all these years. Some of it was shocking to those who had adopted these made up rules from there teachers. When the word started to spread that the earth was not flat, but indeed round, I'm sure the one's spreading that news, which was actually old news, found similar situations.
To me it is really simple. You just have to listen to Korean born masters talk to each other, in Korean. You will hear all these Korean terms used. Hyung, Hyungnim, Seonsangnim, Hoobae, Seonbae, Jeja, Yudanja, Geupja, Kodanja, Sabum, Sabumnin, Kwanjang, Kwanjangnim, Hwejang, Hwejangnim, etc. Westerns might say they are titles. Most all of these are forms of courtesy used in the Korean language.
Westerns, or other nations Taekwondoin then want to know what their title is. The answer is not so clear because other nations do not follow the same society rules of courtesy found in Korea. So as a non-Korean, can I really ever TRULY be a Hyungnim, Hoobae, Seonbae, etc.? I say rarely. But some of these can apply loosely to us. Some can apply officially to us, in special official circumstance.
If our Korean seniors referee to us in any of these forms of courtesy, then, I guess these terms may somewhat, or even fully apply to us.
I think their has been a simple effort to clarify this. Most everyone in Taekwondoin was or is a Jeja (student), most of those were at least a "yugeupja" (geup, or color belt rank holder). Some are Poom holders (upper level child practitioners who are not old enough to have Dan). Yudanja, Dan holders from 1st to 5th. Kodanja, Dan holders from 6th to 9th. Official certifications are issued for these practitioner classifications.
One officially becomes a Sabum by the Kukkiwon, when they pass the test, and are certified as one. Hwejang can come as an official appointment, or election. Taekwondo Kwanjang the same way.
I think it is important to classify that Kukkiwon 1st to 5th Dan Yudanja, and, 6th to 9th Dan Kodanja does not mean instructor, officially it doesn't. Dan has no true bearing on the general official instructor designation. Sabum should mean instructor, you have to pass the Sabum test, not a Dan test.
In the English language, Master can be a formal form related to Mister, and I think used in that way, it is perfect for 1st to 5th Dan. I get his picture of the English butler out to calling "Master Worthington", a simple title of respect for a member of the family or household. In English, I think Grandmaster can also be a formal form of Sir, and I think used in that way, it is perfect for 6th to 9th Dan.
I think when "Master" is used at 4th Dan, or whatever Dan to mean instructor, or now at 4th Dan one has reached some magical level and gets to wear some special belt, it gives false sense of self to that person and/or to those around them, and that is simply wrong according to Buddhist thought, which is Taekwondo thought. But, in a business sense, it makes sense, if that makes sense
I use the "master" title in my school for all Dan and Poom holders, including myself. That takes away the god like status that has been wrongly applied to black belts, and instructors. All my students will tell you that "master" means Mr, or Ms. The only people that referee to me as Grandmaster are my Korean seniors, they use it in public in front of students or at events or on documents. No one in my school calls me Grandmaster. Most parents call me Al, I ask all American born, and non-Korean Taekwondoin to call me Al, unless we are in front of our students, then I call the person by their formal title. I do use the title Grandmaster in advertising though. That is a different subject.
Other wise if we as non-Korean's start using these Korean terms to refer to ourselves among ourselves, it becomes like these guys who join some group so they can now claim the Japanese title of Soke, when if one really studies what a Soke is, no one living outside of Japan could achieve the true designation as Soke.