I'll give you an analogy. Someone has driven cars all their life. What do you think about giving them the keys to a tractor trailer and saying go drive? I don't worry about the damage to the trailer the first time they try backing it into a tight space, but I worry about the first time they face a situation on the road they aren't prepared for and lives are at stake with their handling of it.
However... Hundreds of thousand RV's [20' to 45' / 12K to 40K lbs. ] are on the road... driven by "car" drivers who never before drove anything bigger than a soccer mom type of vehicle. Be very careful when a Big Ass RV starts doing strange things in traffic!