I make a habit of never trusting my instincts over what the math says when I can't see out the airplane window. Your recipe will work, but it isn't the most efficient, or the safest. If you want the spend the least amount of fuel to get to a given higher orbit, you will aim the jets to decelerate your forward motion, and just slightly down toward the earth, hook the jet controls in a negative feedback loop through a gyroscope, and attempt to keep yourself in fixed circular orbit as you rise in one single, continuous blast.
If you simply try to blast straight up, you will then be in an extremely elliptical orbit because you are at the wrong speed for the circular orbit at your new height, which you must then correct. All you gained was a lot of incorrect angular momentum, at the unnecessary cost of a whale of a lot of fuel. If you plan to go to the moon, sure, point the dern thing straight up. But that wasn't the problem that was set.