Computers are—or maybe "were", at the time—something that could be both understood and controlled. If you write a computer program it more or less does what you told it to. You can also inspect computers, and determine why certain things are happening. For a traumatized child looking for a sense of agency in an unfeeling universe, this is a powerful combination. As @nelhage put it, "computers can be understood" https://blog.nelhage.com/post/computers-can-be-understood/ — and I want to believe him.