The Dr.I was undoubtedly a great fighter in the hands of a skilled pilot, but it definitely wasn't the best choice for an inexperienced pilot. The Albatros and the Pfalz, which were used in the same time period, were much easier to fly and better suited to the skills of the average fighter pilot. The Dr.I was also too slow, and while it was great in a turn fight, it really couldn't get out of a fight against more powerful Entente fighters, such as the SPAD and the SE.5a.
One of the most important reasons why the Fokker D.VII was so extremely successful was its benign flight characteristics. You didn't have to be a Voss to fly it really well in combat.