Think about our solar system this way... imagine the sun is the size of a bowling ball... about 8"... in comparison, the earth is about 1/16th of an inch (half the size of a BB) and Jupiter is about 9/10"... Earth would be somewhere on an orbit about 78 feet away from the bowlingball and somewhere on a circle 245 feet around. Jupiter would be 405 feet away from the Bowlingball sun and poor demoted Pluto would be 3/5ths of a mile away. Now, throw several thousand of sand, one at a time, at this model solar system... what are the odds that you would hit the 1/16th inch sized Earth?Over how much time / how many passes / how many other interactions (with Jupiter, for example)? Objects in orbit around the Sun can be in a variety of different planes; however, in the ecliptic, odds greatly improved. And I think we have some common ground as to using supposed odds of things happening as evidence of anything.
I should point out that the current accept cosmology cannot fully account for why there is a plane of the ecliptic... or why the ringed planets have their rings exactly over their equators... gravity alone cannot account for it.