Players like methods with low input value and are simplistic, not having to think so they can do something else on their computer. Barbarian course takes less thinking to gain the max Xp/hr than FPF and so they are more inclined to do it.
While you're here. What method are you doing for agility and how has it been going for you in terms of xp/hour and mental/physical strain. I am doing Barb adv and Gnome adv. I am almost always getting max xp/hr when I'm on and it can get difficult after 18 hours of it straight. :P After long periods I tend to casually miss a tick or two. Any reason to not doing fpf? I'm not really a fan of stored points personally. Courses are more social as well and in FPF you're forced to go as fast as possible. Hard to have conversations when every 7 minutes or so you're lobbying.
While you're here. What method are you doing for agility and how has it been going for you in terms of xp/hour and mental/physical strain. I am doing Barb adv and Gnome adv. I am almost always getting max xp/hr when I'm on and it can get difficult after 18 hours of it straight. :P After long periods I tend to casually miss a tick or two.