The reality is every jail, prison and detention center has rules to enter. The staff have real jobs that have to done every day to protect themselves, the detained and any visitors. Outsiders are in the way, the reason for the visit doesn't change that.
The hard truth is even if the left were right and the accommodations were bad (they are not) it would not matter, most of the illegals are not in them very long before they are processed and sent home.