I've never taken a class in Bagua but is there a belt ranking system like in some other martial arts.

Also, why do some people reject the belt ranking system?

Bagua does not traditionally have a belt-ranking system. It wouldn't be unheard of for a Chinese martial art school like to have a belt-ranking system, but it's a very recent and unconventional addition.

Belt ranks first appeared with Judo, and were later adopted by other martial arts, either Japanese martial arts (karate) or those derived from Japanese martial arts (Taekwondo, Hapkido). Bagua existed before colored belt ranks were a thing. It's not so much "rejecting" it as simply not choosing to add it.

I've never heard of a belt ranking system in any baguazhang schools, but you never know. Some people just don't see the need for belts (like me).

No, traditional Chinese martial arts does not rank. The belt system was invented for Japanese martial arts. Jigoro Kano, founder of Judo to be exact.

There are no belt ranking in traditional Chinese martial arts. One is either a student, a disciple or a master.......

I've never taken a class in Bagua but is there a belt ranking system like in some other martial arts.

Also, why do some people reject the belt ranking system?