So, a Geosychronous Transfer Orbit, gains in altitude, while staying directly overhead at the same point on the earth's surface, even though the earth below is still in rotational motion. But, at points closer to the equator (where much of the good rocketry real estate resides), to keep up with a fixed point on the ground, while traveling farther and farther away from the central axis of rotation, ever greater lateral distances must be covered at increasingly greater speeds.

Meaning, if you can keep your rocket directly overhead, over a zone and airspace you can control militarily (by denying enemies access to it, or maybe by choosing a place that doesn't need to be defended), while putting it as high in the sky as possible, it will be much more difficult to shoot down, providing the advantage of being able to then move this proverbial chess piece into position anywhere you want, without too much concern of being denied access to that perch.