Character transfer gold cap?

I recently transferred to find out that there is a 20k (20,000g) gold cap if trying to transfer to a new server... Why is this? I don't think it's fair that those of us that make a lot of profit should be punished for moving somewhere else. I had to leave a lot of money behind, even after investing my money into items to take with me. I would like a clear reason as to why it isn't any higher?

I would make a suggestion to raise it higher to avoid unhappy customers. The GM I talked to recommended to make a post here because he did not know why this cap is in effect.