You're right
!!
I can't imagine calling myself the way AïkiAlf showed
.
But, it may have a
spiritual meaning (I can't find another word).
Perhaps, Senseïs wanted their disciples to vow their life to the Budo. We may not forget some lived in their senseï's dojo. So, they couldn't do a job
.
I think the suffix
-ka is a way to show that a budo
ka is fully concerned by his/her training.
It may be an explanation why we find
-ka means it's a job.
Don't you think so ?