I'm sure you're right in some cases, but I think there's a balance to be struck. I've worked and interned in recreational therapy and guidance counseling with kids, and while many need structure and boundaries, there's also often a bad combination of no behavior management plus no positive encouragement - people figuring that not be harsh on the kids is enough to inspire them to grow positively. Around here, there has been a lot of cracking down on behavior at schools by administration, with lots of authority figures telling kids they're a nuisance, and the kids feeling a lot of pressure and negativity and not a lot of reward or support. That sort of system doesn't make anyone
want to behave well. There's an old phrase about using both the carrot and the stick - it's commonly used in reference to politics, but I think it's applicable here. If you just use the stick, the mule has no motivation besides punishment. Provide a carrot too, and you're providing a reason to move forwards as well as a reason not to move back.
I think it's important to pull back and look at the bigger picture. If you're an instructor, one of your goals is to teach the kid a particular move, sure. But ultimately, it's more important to have a happy, motivated, well-behaved kid than a kid that can do a backflip. Maybe in the moment you
do need to tell him to shut his mouth and get down to business. But that's not going to work every time, and it's not going to work for long before the kid gets pissed. Encourage him that it's his dream to become a breakdancer and this will help get him there, and he will
want to do what you want him to do. It's the art of getting someone else on your side by assessing how things can be mutually beneficial.
After all, what's the point of being hard on a kid if he's miserable and ends up dropping out? You'll ruin the whole point of the endeavor. I seem to remember that being a struggle for 8s. The 8 will voice something like "I'm doing this for the family", but the family is miserable, having been alienated by the hardness the 8 has developed in trying to protect their family. The "gentle" comes in when you reconnect with the softer side that knows how to collaborate with others.

That's just my theorizing, anyway.