It’s not impossible that the mechanism was selected for maximizing energy absorption within the sunlight’s spectral distribution, depending on which of these curves is most relevant (e.g. incidentally the green curve): https://commons.wikimedia.org/wiki/File:Spectral_Distributio...
Leaves aren't even very green, if you look at the full spectrum of sunlight. They only reflect around 10% of green light, while they are more like 90% reflective in the infrared. So you could say that leaves are infrared. It's only our eyes' receptors that see them as green, since they are not sensitive to infrared. (And they are, for most plants, not a very bright green.)
Green is what is reflected, not absorbed. And green is higher-energy than red, so naively one would expect that plants should rather reflect red than green. However, I tried to point out with the link that things might not be that simple; though I really don’t know.
