I agree with you, although I should note that the current Navy railguns are not capable of putting shots in orbit. However, the logic behind choosing guns over

I agree with you, although I should note that the current Navy railguns are not capable of putting shots in orbit. However, the logic behind choosing guns over elevators is simple: I. Actively supported towers are easier/more likely to be built than a space elevator made of unobtainium. II. The technology to build a space fountain or actively supported tower is more difficult than a gun, because you first have to have a gun which can shoot objects faster than orbital speed, and then add the recirculation plus the momentum transfer to the tower. So, an orbital gun is a subset of the technology needed for an active tower. One other thing which is often overlooked when discussing shooting stuff into orbit, is that the size and cost of the gun is proportional to the size of the projectile. If shooting from very high in the atmosphere, very small projectiles could work without significant atmospheric losses. A railgun or light gas gun on an airplane could easily shoot literal tons of small projectiles, machine gun style, then land and reload (and with current tech, replace barrels). If a target in orbit was shot at, you wouldn't even need to have a rocket in each projectile to provide thrust at apogee. Instead, you hit the target and embed into it. By hitting the target at different parts of its orbit, you avoid substantially changing the shape of its orbit, balancing out the momentum change to keep the orbit how you want it. This wouldn't work for anything besides bulk materials which can be broken down into small pieces and shot like tiny bullets out of a hypersonic machine gun. But the cost per kg for bulk materials could be very low.