Nintendo still sells the original mario bros. game through multiple avenues. This site existing absolutely takes away from Nintendo's profits off the game in a real sense.
Note, virtually all works are derivative works, except that now, we're only allowed to derive from stuff created at an arbitrary point when copyrights became perpetual.
If this mario game was allowed to benefit the many users it did -- would Nintendo lose their incentive to create new games? Would it make Mario not profitable to develop retroactively?
I think the answer to these questions is clear. As is the fact that society is deprived of a huge amount of value here.
the law says it is not,case closed.
I think the answer is obviously not. Therefore, depriving society of this value in order to incentivize Nintendo with higher profits is a bad deal.