It's not friction that creates the massive heat, it's compression. Entering the atmosphere at the speeds that stellar objects and orbiting vehicles do turns the object into essentially a large diesel piston. The air in front of the object can't move around it fast enough and instead stacks up and compresses, which causes the molecules to gain heat. By the time the object slows enough, the heat is immense.

That being said, I want people to think about what effect compression intense enough to burn up meteorites would have on a squishy human body. The cosmonauts' bodies would be utterly destroyed long before they could burn up, like stepping on a tomato.