I think the reason is because most of the youths in our country believes that our educational system has failed us, and if you look at it very well, you will notice that there is truth in that, i mean i see no reason why a naija youth would spend years in school, make first class and good grades, only to graduate and get fucked up by the labour market. no job opportunities for the youths, even the ones wey manage see job, na peanut them go pay them, seeing all these thing, do you think youths will be enthusiastic about attending lectures or making first class? back then in the 80s as you mentioned, people who graduate with good grades often get the opportunities to do their masters abroad, where we all know that they can potentially be exposed to a much better life and opportunities, some even end up being retained there and many other things, but today, there is absolutely nothing like that, nothing to drive students to work harder and push pass their limits, they feel like the system isn't worth the effort and honestly, i dont blame for thinking that way.
All still boils down to the corruption we are talking about, the system now is very corrupt that you do t even know how to sensitized it because it starts from the up to down what do you expect when all you see nowadays is parents buying results for their children and paying to sort courses, paying the have good results for their children from primary, secondary and tertiary, so that they don't fail any exams, in common entrance in some states you must pay extra fees to support you child in the examination hall, you cannot resist it, it is a must and the education system is aware and not saying anything, they will not isolate your child if you don't pay on it before that day, they will add that bill when you want to collect your child's certificate, if this is happening in a primary school what do you expect in other higher schools, that is why we have half-baked graduates, for the ones that really took their time to study also suffers these corruption in the labour market since it has to now do with connections.