"No teenage brain is. That is why parents also have to instill a reasonable work ethic and show them algorithms for reaching goals"
As the parent of an almost teenager I would say you are wrong. My kids will have a great work ethic, about things they enjoy. Obviously not everyone has the same interests.
For me, when I took programming courses in highschool, it made me realize how meticulous you would have to be to do it correctly. I would spend hours hunting down syntax errors (no internet back then) only to find out i put a comma in the wrong place. Math, I never knew why you would need it because we had computers and calculators. The theory was interesting but repetition - hell thats why we developed computers! to do the same low level repetative tasks over and over.
I loved taking apart computers, electronics, cars, etc and could do it for hours at a time, and I still do. So its not necessarily laziness. I just didnt see the point of doing the same math problems over and over when a computer could do the same operation a million times faster.
tldr, everyones interests are different, even "lazy" teenagers.