Emulated servers take time and resources to perfect is my point I guess. Much of the time the information/values used are best-guesses and approximations, some code has to be re-written from the ground up. It can take awhile for an emulated server to reach the same level of parity of it's officially supported sibling to where the average player wouldn't notice.
I play EQ Emu and nothing is ever perfect, more than 10 years after release. Things taken for granted in most games are still being patched in to this day. I'm not disagreeing that it would not be a superior product eventually, just saying it wouldn't be as instantaneous as any other pirated/cracked game (like Diablo 2) that isn't filled to the brim with other MMO trappings and for all intents and purposes basically IS an MMO. It's different this time.