"Clutter" and "Complex" are two entirely different animals. A cluttered avatar is what happens when a person just throws a whole bunch of stuff on without being very selective, and it has the effect of mixing prints with plaids in real life. Cluttered avatars do not cohere into one solid outfit, and pile on more and more layers just because the colors match. The color balance and weight are normally off.
Complex avatars, on the other hand, are avatars with many small details that are carefully chosen to aid in color, theme, and skin distribution.

These avatars are cluttered.

These avatars are complex.
See the difference? It's the complex avatars that get good rates, because they're planned well and look nice. Clutter is by definition incoherent, so it will never look good.