The current solution messes with the WOW TBC Gold very premise behind the game of two factions. It's been the very base of Warcraft since it's inception. Giving free faction changes (mind that they could restrict this to once per account on the number of characters), so people can change the entire character of their characters, would be an ideal solution.

It may seem like a simple solution to just make it impossible to create new characters on horde, but the implications and the backdraft would be huge with plausible arguments such as "I want to play with my buddies" or "I would like to be a an horde character because I like orcs."
In addition, you'd need limit the creation of horde characters to all server in the bg pool. It's not possible or even practical.

People had the opportunity to exchange shortet queue times for a considerable amount of time. But they didn't. They didn't utilize the servers for free transfers. It's not surprising for me, as the majority of players play their favourite side or where their friends are. It is hard to change this.

"I would like to play with friends" is an argument that is not very convincing to not have balanced servers or Bg pools. In addition, making faction change possible, would mean they could join with their buddies as an alliance instead of playing as a horde.

Transferring servers isn't easy. It is impossible to tell if the intended realm is as good as your previous and it doesn't matter if there's no queue, it could be a disaster and even dead world. Vanilla was the first time I've seen this occur. My guild was moved to a different server, and within some months, the population had dropped to just several hundred during high-traffic hours.

While it's true that no one has been allowed to change characters their characters however, they could have if they felt the queues would be too long.

The arguments against server transfers are also relevant for switching sides. It is impossible to know how many people will be able to support long-term raiding or other content. While there may be less waiting times, you'll not be able fill every raid within some months. While it's on the buy WOW Burning Crusade Classic Gold same server, each side has a completely different growth rate and mentality of players. How can side transfers help even if server transfers were not for mostly the same reasons (queue times)?