I think the topic was made more or less because people will choose to leave FFXI for FFXIV based on the beta most likely. If the beta does not live up to their expectations, they may very well call it quits on FFXIV and just keep going with FFXI, on the other hand if the beta is amazing, they will likely plan to say goodbye to FFXI when the release for FFXIV approaches. I doubt people would actually leave the game for a beta, as it has been said in this thread a few times, however if the beta is good, I can easily see people getting ready to pack their virtual bags in preparation for FFXIV once they see how good the beta is.