Because Triss, merging literally every single server together creates an overcrowd (Shocking but true) people will be complaining that their nm's are being overcamped, people will rage quit because no can get anything done due to this congestion. If you say maybe merge them into 3-4 servers then that I can see, but you'll still have people butthurt over 'omg I've been on this server forevers, I can't stomach the thought of moving' so how are you going to survive when XI is gone completely? Be thankful we can still play this game.

Personally I'm against the idea of a huge server movement, too many people would stay rooted on their home turf and the people who do move go into ghost towns, and eventually quit.