Rockets essentially mostly consist of things that are intended to go boom with very little prodding. On top of that, the force on a rocket engine makes it prefe

Rockets essentially mostly consist of things that are intended to go boom with very little prodding. On top of that, the force on a rocket engine makes it prefer to make the rocket engine go through the rocket rather than pushing the entire rocket itself, and it requires careful engineering to make it not do that. Combined, this means that if anything goes slightly wrong, it tends to cascade into going horribly wrong and cause the rocket to explode. In this case, though, it seems that the guidance system or something similar was going wrong, and the rocket was intentionally blown up in a safer location than an uncontrolled trajectory might have taken it.