[Loser]

Actually the particles, orbiting a larger mass, would be traveling at different speeds based on how far away they were from the mass they were orbiting. As they clump up, they must travel at different speeds, and angles to each other. Then, once they are starting to form a body, there will be many bodies clumping together, pounding and knocking each other around. Since the bodies do not intersect through their collative centers of mass the impact would necessarily impart spin.

As for galaxies, they must spin or all matter in the galaxy would fall into the center. The orbital motion is all that keeps them apart from each other.