The roof should not look like that, in only 6 years, unless the cleaning product caused a breakdown, possibly salt water air? The cover may not have been as breathable as advertised? These roof types often carry a 12 year warranty, and can last up to 20 years, in the right conditions.
The Dicor does not look bad for the age, but does need to be cleaned, and a light layer added.
My FW was bought new in Aug 2012. It sits outside, in the midwest year around, gets tree sap, bird cr@p, road dirt, and covered with ice/snow all Winter. I've washed it 4-5 times, added a protectant once. I have added fresh Dicor, as needed, but my roof looks way better than yours.
Something seems to be causing yours to deteriorate prematurely.
Jerry