The problem with this is if you toss a chunk of raw steel, no matter how fast or at what angle, it will always simply fall back down [1]. The minimum payload for this system absolutely requires a (extremely robust) rocket engine and propellant and avionics to circularize the orbit at apogee. That's the only way to achieve orbit. That puts a disappointingly high floor on the cost per launch and launch rate.

[1] Technically, escape velocity is also a possibility. But it's not a useful one, as the payload is still lost.