They told me that it "creates too many sources of truth." Honestly, that was the exact phrase.
They are concerned that if you write something free text that could be interpreted as conflicting with something checked off in the check boxes, that it could invalidate your charting as a defense in court.
Also, it is a hell of a lot easier to get people to lie by checking a box than to write the lie out long hand. When you are desperately understaffed, and don't have time to do more than the minimum care, but know you are expected to have done everything, they know they can get you in the habit of checking the boxes that say that the work was done. People wouldn't be able to bring themselves to write that they had repositioned the patient q2h when they knew they were lucky to see each patient once every 4, but they will check boxes saying it happened. Some hospitals don't care about whether the patient really gets turned. They just care that when the pressure ulcer happens, they can deny liability. That may not be as true, now that they don't get paid if the pressure ulcer happens, but it was a fact back when I was a floor nurse.