There's some pretty fundamental problems with spin launch. Atmospheric drag is greatest at sea level, and drops as altitude increases. A traditional lift vehicle is traveling slowest during the early parts of its ascent, and starts reaching high velocity once it's cleared the thicker parts of the atmosphere. In contrast, spin launch is at its highest velocity (before the rocket engine ignites) right after it's releas…
It's good for some kinds of load, just need to know which kind