As you put it "Respectfully, your opinion is narrow"
. You come from a place where full time dojangs are the normal situation and it's hard for you to put your head in the mindset of someone who doesn't EVER want to do that. And it seems from your writing that you feel they should never head a dojang if they don't.
I earn very well from my day job and I love it; Taekwondo is my hobby and my passion. Pre-covid (in the UK we're only really just opening back up) I had 90-100 students, and we'd train 2-3 times per week (two evening and one Saturday morning).
I teach Taekwondo for the love of it, not for money. I don't ever want to earn money from Taekwondo. Our students pay fees, and they go to the hall hire, equipment purchase (such as mats), instructor education, etc. But myself and my master assistants don't take a penny from it.
Personally I feel that if you're doing it for the money there's always going to come a time where you have to chose between the financial side (whether it's "I want $X,000 per month" or "I need $X,000 per month to keep the dojang doors open") or your morals. Do you test/pass that student that really shouldn't. Do you accept more students than you realistically can teach in a class because you need their fees. That sort of thing.
Now I don't look down on those people and say "they shouldn't be a dojang owner, because Taekwondo is not about money, it's purer than that", horses for courses. I just don't ever want to be in that position, but I'm maybe a bit crazy about it. For example, I judged at our national poomsae championship in the UK, and the organisers didn't know what to do when they tried to give me the daily stipend and I told them I didn't want it, and to give it to some national squad member or student that could do with it.
So I feel that not everyone is a full-time instructor, but hopefully all instructors want to upskill and I don't think "figuring it out" is always the way to go. For example, I don't want to experiment with ADHD or autistic students in the hope I figure it out, I want to talk to experts and take advice so I can best help them. And because this isn't a full time thing for me, attending LOTS of training events on different things could be cost or time prohibitive, so getting a little bit of everything on a single course is great.
Absolutely, if someone's running a business and needs help, then take a business class. I'm already a businessman outside of Taekwondo, so that isn't a problem for me
Again though, everyone's needs are different. For you business stuff or how to build a syllabus or how to teach in different styles may be filler, but to me basic techniques and Korean terminology would be filler because I'm really confident on both things (having done the master course twice, the examiner course once and being an intermediate/advanced Korean speaker.
However, I understand that it wasn't always the case for me, it certainly won't be the case for everyone on these courses, so I appreciate that it's on the course for everyone to learn. And hey, if I pick up some little nugget/tip in that lesson too, that's great - I'm all for learning.