The reason to use "Elsie" is to let the public listens to the song first, before they find out who sang it. From the company opinion, they are worried that the public won't give the song a fair chance if the public is to learn about the singer first. That's how bad in Korea for T-ARA. However like Eunjung said, the plan didn't work according to plan as everyone knows who Elsie is.
We don't need to change what had happened but we must learn through experience and reflection. At the end of day, we mustn't live with regrets. If we think we've done enough, we don't need everyone to agree with us. T-ARA 10th anniversary? Give me 20th.