I think that the OP has a point. If the Lounge had a notice at the entrance stating something like:
In this lounge we have areas where children can play, and adults can have noisy conversations on their telephones.
Please keep your noisy children and adults in these areas or stay outside.
Then there is a clear code of conduct in place. This is much like a dress code in a restaurant, it simply states "please respect our standards if you wish to enter".