The only thing that I can think of is the different polarities, because Methanol is polar and Hexane is non polar. I know that the cannabinoids are non polar also, and so would be dissolved by Hexane. But whilst trying to find out if I would be correct in saying the Hexane is better suited for the extraction of cannabinoids, I found out that Methanol is amphiphilic and so would also dissolve non polar molecules. So now I'm really unsure.