So, reunite kids with people who have said they're related, in the event that the kids and their parents separated before they reached the border? Read the article before rebutting that.
I would bet that everyone being held is better fed, housed and receives better medical treatment than they were before they left and I doubt they had cleaner water. They're also doing DNA tests, to find out who's related, or not.
So, you want to just let everyone through? Where will they go? Where will they live? How will they provide for themselves and the kids? How will they receive medical treatment? If they have no way to address these questions, they're better off in the detention centers.