One reason is that Direct Instruction, at first glance, looks dated. Indeed, teachers who treat their jobs as a cross between stand-up comedy and the Superbowl halftime show might, after peeking into a Direct Instruction classroom, disappear faster than a spare textbook at the Board of Ed. To make matters worse, these methods owe a lot to the late B. F. Skinner, the Harvard behaviorist some recklessly called a fascist. That's unfortunate and unfair, because Skinner demanded a scientific approach to classroom instruction, which is lacking from almost every hot reform idea du jour. Direct Instruction stresses basic skills, breaking them down into mini-components.
Children learn to read, for example, by learning the sounds of the letters before the letter names.
They master each skill before moving onto the next one. Teachers track each student's progress on daily charts. They also track behavior, encouraging good conduct with praise, while ignoring bad behavior for the most part. In short, if you can't measure it, you probably shouldn't teach it. This kind of micro-management is almost unheard of in most classrooms.