To limit the probability that gypsum board will be crushed, which could lead to inadequate support for gypsum board, which could lead to an inability to resist expected impact, gravity or lateral loads.
This is to limit the probability of the deformation or detachment of interior finishes, which could lead to:
Where walls support floors, this is to limit the probability of deflection or vibration of such floors, which could lead to negative effects on the psychological well-being of persons.