Well what you have stated are mostly personal opinions. Others might have their personal opinion why they like the e92 m3. I could think of 2 reasons right on top of my head, it's new, new vehicle generates more excitement. Second is it probably won't have the engine problem e46 m3 suffered from. Which is my main reason I did not go for the e46 m3. Otherwise it's a no brainer i can get an used e46 for mid 30k vs. 50k for an new one.
I do agree with you the interior has gone down hill. I was playing inside of a e92 328i coupe last week and the plastic bits felt just slightly better than plastic used in Nissans or Hondas.