The very beginning of that video states exactly why he is able to hold that animal, venomoid, and thats sick and messed up. But I have seen enough with venomous and even some non venomous that not all snakes can be 'tame'. I think its easier with constrictors, especially ball pythons, their natural response is to ball up and hide, not strike. There are many snakes that when they feel threatened their natural response is to strike. Its just not worth the risk to free handle venomous. Heck even dogs can snap and maul their owners or others.