Here's another reason why ENY is a good thing...
I spend lots of time in Early War, some time in Mid War, and starting to spend some in Late War. After my first 6-8 months in-game, and flying the Hurri 2c almost all the time, I was getting very bored at how quick and easy it was to kill people. I'll tell you, something; I was real close to quitting altogether because it was so boring flying the uber plane that could blow anything apart just by looking at it. Every now and then, ENY forced me to jump in something else, like the A6M2, F4f, etc. and I was the suxxor because it forced me to try to fly smarter and it took more effort to kill someone - many times they'd reverse on me and kill me instead. But I was having more fun.
After trying various "sucky" planes, I found the Hurri Mk1. It was the breath of fresh air that sparked my interest again. After a couple of weeks I got used to the carb and was able to fight without killing the engine. After a couple of months I found many things that the plane could do that surprised people. I even started to see others upping the Mk1; perhaps to see why they kept getting shot down.
Without ENY forcing me to fly "lesser" planes, I would never have tried the Mk1 and probably would have quit after a year or so. To me, it's all about the fight - win, lose or draw.