Men did not have the same opportunities as the
other races. The other major
race is the
Elves, and the single biggest opportunity they got was an invitation to
Aman. That is not to say that Men should have got this opportunity, it is just an example of one they did not get. Likewise, it seems the elves got no instruction direct from
Iluvatar in their early days, as did the Men.
As for fair treatement, it depends who was doing the treating I guess.
But if you look outside of the history of
Middle-earth, and to th way thay men are/were to become... I think it is obvious that Men treat Men most unfairly.
By other men, I would say yes, as least when compared to the treatment of other races by men.
By the Eldar, I would say often.
By
dwarves? Yes.
By the
Valar and
Maiar? Hard to say. The Valar did care about men, and we are even told that they love men, but they appearantly work in mysterious ways. They did not take as much action for men. Could be they were not supposed to. But Men were aided in the WotJ and WotR by Aman.
As for treatement by
Eru? Only
God could say, I think. The very nature of the
races is the most important part of this package I think, that and their fate. Who can say which race will have a superior fate?
By
Morgoth? Well men were more fundamentally effected by
evil since they fell to it as a race, but aside from that I think all races were treated with equal unfairness by evil.
