"Nonparametric" methods focus on the observations too much. It's better to change representation from raw data to something else. The specific stressed in nonparametric methods is that there is lots of data, and it's possible to easily run requests on that data. At the same time, representation with too few parameters can present the results directly, but fails to be useful for different kinds of requests. The right balance is somewhere in between, with lots of data allowing to run custom requests, but only data that is expected to pay its rent. Parametric approach, but with many parameters.