Can someone explain why kpop companies enforce dating bans?

For example, recently 2NE1's Sandara and Bom were released from the dating ban and are free to see whoever they want. Do companies do this to make the singers focus on their work? Or is it for other reasons?

My guess is that the idea is there in order to keep the group together as long as possible. So there aren't any 'outside influences' trying to change the artists mind about their career (so there isn't any pressure for marriage, children, etc).

Maybe the labels think that it will kill the group's appeal. Depending on their fanbase, a fan seeing their idol dating someone could make the group less appealing. If they see them as less appealing, they will be less likely to continue to support the band (through buying merchandise). Less support = less money.

I'm not sure if that's right, but it makes sense to me from a business standpoint.

i think it could be possible that the company doesnt really care if they date, but if the idol gets spotted with a "lover" they get twice the attention because its forbidden. i'm probably wrong but it would be cool if that was why. conspiracy..... ;P