Yeah. The problem is that no one here seems to know any facts about GKYS and seems to judge it based on no knowledge and eye-view perception.
I just want to clarify that...
1) Gongkwon Yusul is not a copy, or an offshoot of bjj or any other styles like sambo.
2) Gongkwon Yusul is not a fraud or scam by bjj guy to make money. Founding master never took bjj and bjj came to korea in 1999, 3 years after gkys was created and founded.
3) GKYS is not an offshoot of hapkido or some supplimentary syllabus for tkd or hapkido people
4) GKYS IS proven to be effective. The GKYS master in brazil has his students compete with much success (win/lose record wise).
5) GKYS did not copy any martial art's name.
6) GKYS looks like TMA and has aspects of both modern and traditional MAs.
7) ITs founding has nothing to do with BJJ or mma since neither of them existed in Korea in 1996.
Gongkwon Yusul is created in 1996 by Kang Jun who was already a martial art master in hapkido and (though not impressive) judo champion during highschool, and has other MA backgrounds in korean and japanese TMA. He took practical aspects of MA's he practiced and combined it into a street-effective style with syllabus open for further development (like jeet kune do has). GKYS stands today as a legit MA. The reason people criticize it and talk shit about it is mainly because it is not practiced in US and people just dont know much about it.
Source: gongkwon.com