What Do Cross-Realm Battlegrounds Solve?

This question seems to be getting more and more play on the forums recently - and I can certainly see where this poster is coming from. When I played Alliance myself, I rarely participated in PvP battlegrounds for the same reason - queues tended to last about an hour and I always seemed to think up more interesting things to do than wait around. When I started playing Horde, I found myself doing battlegrounds much more frequently - and would consider ten minutes to have been a long battlegrounds queue. However, if most realms have higher numbers of Alliance than Horde, won't the problem be the same, only on a larger scale? CM Nethaera explains that "some people may see their time go up, others may see theirs go down" - as populations and queues are averaged across many realms. However, Nethaera also notes that cross-realm battlegrounds have not yet been tested on the test realms - and, in my mind, any test realm environment still won't give us a good view on how this will impact the live realms.