I agree with the gentleman's comments, but he not quite correct when he says "If Neptune had cleared its zone, Pluto wouldn't be there,"

Neptune and Pluto are locked in a chaotic orbital synergy, the latter was never ejected because of an orbital resonance that guarantees that everytime Pluto is vulnerable to Neptune's perturbations, Neptune is on the other side of it's orbit. It's an anthropic thing. Pluto isn't particularly special, just lucky. There were probably at one time many other objects similar to Pluto who were bumped into higher or lower orbits, and only Pluto survived because it just happened to be in resonance with Neptune.

I wish this story would go away. The IAU really blew it.