Planets/Moons spin axis question

[rodin]

What couples spin in the Solar System? The fact that most spin axes are (crudely approximately) orthogonal to the orbital plane cannot be a random occurrence

[astromark]

Pull the plug on a bath... Its the same force. That rotational velocity is movement exaggerated by the coalescing mass. Your bath tub water does it, as does the galaxy., or Solar system. This over simplification is only intended to help you understand that force. Driven by gravity and compounded by rotational velocity.
The use of your word couples is confussing... connects, causes. I understand.

[Tim Thompson]

Conservation of angular momentum. The system starts out before fragmenting as a single rotating proto-planetary disk. So naturally as it forms planets & a central star, they all tend to share the rotation & angular momentum of the original disk.