There just seems to be an inherent lack of enthusiasm for server transferring to a single PVE server to meet the needs of PVE boxing - people feel comfortable with their current server, or get discouraged about moving after having experienced the ever shifting boxing population (let's face it, most of us go through periods where we are sick of the attention or effort boxing takes and just want to do something different). It's not fun to move to a server for the community just to have everyone disappear.

The other issue (affecting aussie boxers at least) is the latency issues with moving to particular servers. I attempted to box on Magtheridon at one point because of the great community, and had to abandon my characters because I could never get better than 500ms latency. Now I have moved to Caelestrasz (PVE) and am loving the environment and people that I know there, so I would be reluctant to shift a bunch of characters off even to another server in the same data centre.

Cael also has an emerging boxing community; still too few of us to be able to schedule big things often or reliably, but there have been periods of great fun and activity.