Unfortunately, anything they could do to reduce the effort at the lever would require them to also spend money on the entire clutch system to increase the torque capacity. So far Harley's answer to increased torque capacity, over many years, has just been stronger and stronger springs which is the cheapest way to bandaid the problem. They are leaving it up to the individual riders to spend the bucks, which is the way they tend to deal with most of the other shortcomings of their products. Get used to it.
One solution that allows for the use of "softer" springs is the variable pressure clutch you can find in the aftermarket (see the post from BALIS above). That design uses centrigual force and weights to increase the clamping load on the clutch plates as rpm's increase, so the springs don't have to be as strong. I haven't used one myself, but there are some folks on the site who have. Perhaps they will share their experiences.
Jerry