NumPy ndarrays do not have nanreduction methods like nanmean

In [1]: import numpy as np

In [2]: np.nanmean
Out[2]: <function numpy.lib.nanfunctions.nanmean>

In [3]: np.ndarray.nanmean
AttributeError: type object 'numpy.ndarray' has no attribute 'nanmean'

Dask.array follows this example and has nanreduction functions, but not methods.

This is sometimes confusing. Do we want to add nanreduction methods to the Array class? Is there a reason that these aren't present in NumPy?