Assuming this[0] is accurate, it looks like solar irradiance reaching the surface is pretty flat from mid-blue up to red, including green. I would guess either there are other evolutionary reasons for reflecting green, or no reason at all and chlorophyll happened to be the first/easiest substance to evolve for photosynthesis.
[0] https://en.wikipedia.org/wiki/Sunlight#/media/File:Solar_spe...