In Monster Hunter, Rarely would a party disband because one player obtained a rare material. Because of the fact that, you do not need only 1 material to create the armor or weapon, you need a couple of common drops, a handful of uncommon drops and maybe just 1 rare drop. So in the process of farming with the same team, other players are rewarded too, so by the time one player has what he all needs and decided to call it a day, other players have also more or less obtained several things on their part.

Point here, EVERYONE is rewarded, unlike in Ex Primal only 1 is rewarded. If you consider 10 tomes as a fair compensation for the item you did not obtain, then it is fair I guess.