Can anything good come from Men?

[William Cloud Hicklin]

Well, the North = Evil, contrasted with Northern Men = Good, was I think something of an accidental artifact of the development of Tolkien's geography. As he shaped the Third Age and its lands, necessarily it had to spread out east and south of Lindon/ancient Ossiriand, because north and west were taken. But the strain of 'goodness'; ie Eldar and Edain, were firmly associated with Beleriand and therefore what became the northwest corner of the inhabitable lands. Once you've postulated that Goodness maintained itself in Lindon and its eastern outpost Rivendell, and that the Edain's kin lived along their line of march east of the Ered Luin, then you wind up with the native Edainic Men and the returning Dunedain so situated.

(Of course, T was also 'calquing' upon Europe, where the barbarian waves have always flooded in from the limitless east and to a lesser extent the south. Vikings of course don't count, in Tolkien's mind)

I also think it may be true that [Elves] were by nature better disposed to be "good",

Remember, it was an essential ingredient in Tolkien's conception that Men had 'fallen', whereas Elves were unfallen. Men were tainted with Original Sin, while Elves were not: what this means is not that Elves were incapable of wickedness (duh); but rather that Men from the time of their subversion by Satan/Melkor are particularly susceptible to the temptations of evil; that it takes an effort of will for Men to be good.