Because nobody wants to do it because it costs them time, and puts them at risk.
If they offer them for money, I'm sure it would be. But if you can't find someone offering them for money, then no.
Because it's too much trouble to be testing single people piecemeal. Testing a group is easier because you do them one after another and then go about your business.
____________
"May the Grace of Ara go with you, and His Vengeance be wrought upon your enemies."