The Fokker D.VI was well-received, a winner of the Idfleig February 1918 Fighter Competition (complicated but technically a merging of Fokker test aircraft V 13 and V 9 became the production D.VI).
It had a decent performance, climb not far off the Mercedes powered Fokker D.VII. The orders were only cancelled as the Fokker E.V came along and won the next competition, so they simply replaced remaining D.VI batch of orders and went for the E.V.
The original orders were for 120 and 150 (270 total) but after the first 60 aircraft were delivered, they switched deliveries to the E.V instead.