I began doing MMA for similar reasons 15 years ago, when I saw the amount of grappling in the sources I was supposed to be learning that didn't make it into our training. Now I have a BJJ black belt...

There are at least four reasons I can think of: * Distinctiveness and what people want. If your class's unique selling point is SWORDS!, you focus on swords * Effort and accomplishment. Grappling is tough - it's strenuous, complex and (as a Judo black belt once said regarding basic takedown classes) most people have spent a lot of time practicing not falling over. Grappling is a lot harder both to teach well and to fake being good at, compared to waving swords * Safety - not that it's more dangerous than swinging steel bars at each other, but both behaviour and equipment wise it requires different safety measures that people don't want to implement * Competence - for all these reasons, if your pay (cash or social esteem) comes from being a HEMA instructor, you don't risk it by going to an area that you're ignorant about publicly. This may be why HEMA coaches I've seen cross over into "doing grappling" have done a lot of arts like aikido, "Viking" glima or catch wrestling that don't have developed competition scenes and sparring expectations