One of the major concerns would be progression. How would you feel that your character is getting more powerful? Is that even a concern to consider? I feel that it is but I am no expert. Would you get higher item level gear each expansion? Would you abilities just start doing more damage/healing each expansion? Part of the reason players play games is to have their characters grow and become stronger.

I personally liked that many of the things in 11 stayed relevant years later. Not having everything I did last expansion relegated to a gear locker or the vendor was a nice feeling. I assume I am in the minority here though.