OP many things are wrong with this your post. First, young Nigerians are hardworking and not indolent. They strive to learn and benefit from anything worthwhile. That is why you seem Nigerians dominating in anything they are involved in that is worth their time and energy.
In contrast with OP's opinion, Nigerian youths are super hardworking, especially amongst our peers in other developing countries. One could say it is because of our resilience, consistency and our ability to survive in harsh and tight conditions.
It could be as a result of our system of governance where the young people are availed with little or no opportunities and further downgraded by their efforts tomake their contributions to the government of the day. Yet, we are the largest workforce in the nation. The older guys in their septuagenarian and octogenarian, have beclouded the space with their influences and will only allow you to perform as a drudge.
Another things is that any young man still depending on the parents, when they should be on their own, ia definitely in serious pain and never enjoying it. It can be a case of "na condition make crayfish to bend".
Lastly, the percentage of Nigerian youths involved in illigal is very small and never enough to use and generalise. Illigal na bad thing anyhow you view am so many people are only joining it because of peer influence or condition, although no justification for evil.
The system have already been designed in an aristocratic manner in the sense that you are denied the very basic rights and privileges you should enjoy as a countryperson. You are being denied the very basic amenities and access to the resources of the state for good use like grants, softloans and the enabling environment for the small and medium sized enterprises to thrive.
Why won't they remain under their parents when there's no reward to hardwork and no opportunity for good works. You will work a whole day just to have little food on your table whereas in more sane and developed worlds, those are some of the high paying jobs as a foreigner.