That's not true. They all have some sort of thing that drives them. For some it might be football, for others it is making up stories, for yet others it is coming up with drawings of weird mad-professor like castles, fashion, a certain genre of music, food, cooking, decorating things you name it.

The one kid that I ever encountered which I didn't find something that I could leverage to get their intrinsic motivation was a very young syrian refugee child who must have been so severeley traumatized he barely remembered my name despite seeing me every day – he was 6 years old. With him it was like working with someone who had dementia, you could only get him for very short periods and do something and he would completely lose it the day after. Most times it seemed like he wasn't there at all mentally.

But for all the others it was just about finding a way to connect certain topics to their field of interest. E.g. xkcd-style calculations for catapult with the "mad professor" as a trojan horse to physics he tended to hate before that, doing record sales calculations with the hiphop guy, writing a text about a soccer game with the soccer guy etc.

Of course sometimes they just wanted to do nothing, but slowly connecting the stuff they were forced to do before with their interests was something that showed tremendous effect. They were gladly coming every day (most because it was worse at home). If someone is stressed they cannot focus unless you make them care and motivate them.

Edit: as you can imagine, this is not the easy route to do that job. The easy route is more authoritarian.