This issue has two sides, really.
On the one hand, I can identify with everyone that says they would like to be able to choose their servers. I haven't really played XI for a couple years (minus the odd fully devoted month here and the $400 out of my pocket for the total play time that I didn't use there…), but even after two years, I've still kept in touch with a few of the closer friends that I made through the game. I would definitely like to have the opportunity to play XIV with them, as opposed to starting over entirely and having to build all new relationships.
But on the other hand, my point above is exactly what could become a problem if they do allow each player to pick their server. You'll get entire linkshells jumping from XI to XIV together, which could potentially cause problems for the other, newer members to the FFMMO world. Obviously that is something that happens over time, but in FFXI, at some point everyone didn't have any friends. Part of the fun of the game was to meet new people and build relationships with the people with whom I was playing. If everyone enters into XIV with pre-determined friend groups, it could take away what was, for me, one of the most appealing aspects of the game, while also making it more difficult for the truly new players to integrate themselves successfully into the community.
So it goes...