Okay so 2 Macaws like the ground out of the many Macaws we all own here on this message board. Lets go with this for a moment. I see you standing on a ladder in battle with a Macaw that 1 does not know you, 2 does not trust you,3 trying to get a towel over it's head, 4 using a glove that the Macaw can easy bite through, 5 you falling off the ladder from the pain you are in because now your hand needs stitches, the towel falling off the macaw, the macaws flies into an object in the room harming the bird now you have the person and bird that needs Medical.
This message board is to give feed back to those who do not know what to do and we talk from our own expierences.
My Macaw hates the floor, My Macaw is a one person bird and hates my roommate, if my macaw were to find himself on the floor, my macaw will step up very easy on my roommates hand just to get off of the floor.
In the wild, you are never going to find a macaw on the ground unless they are dead or a palm nut of food fell to the forest grounds and even then, I would doubt you would see them on the ground.
your Macaw has learned that there is no threat to them on the ground or perhaps you play with them on the ground and this is the reason they like it. If you took a poll here on the number of Macaws that perfer the ground over a perch, cage, playstand, the ground is going to be the last of these choices.
When a Macaw is out of control, trying to handle a macaw is far more safer for both person and Macaw if handled from the ground then ontop of a cage.
But what do I know, I just so happen to have raised Macaws from the time their are hatched, trained, broke behavior habits, give time to local rescues and handled macaws that most people would not go near. just saying