As I said, this is nonsense. The compressive strength of steel as a material is exactly the same as its tensile strength. A steel spoke is a slender column, which buckles under compression and the material itself remains elastic. The only material parameter that is pertinent in (Euler) buckling is the elastic modulus, however, the geometry of the cross-section of the structural member plays a far greater part in determining it's capacity. Same for any other other material; there is no "squishing" involved (the proper technical term is yielding). The suitability of a particular material for use as a structural element in a particular application is determined by many factors, including ability to form and shape, ability to be joined at connections, ability to be manufactured with consistency and reliability.