Like everyone else -- double checked the OP's math and it was correct.

The reason that the climb LOOKS like you're ascending the Matterhorn is because of the severe difference in the dimensions used between the y- and x-axis.

Have a look -- for the same length up the y-axis (2200 ft), you cover a distance of roughly 22.5 miles! (that's eyeballing it) -- so the reason the pitch looks so steep is because you're using wildly different intervals on the two axes. If they were the same, the x-axis would extend out from where you're sitting to a point roughly beyond the livingroom couch and nearly to the toaster in the kitchen (at least from where I'm sitting :-)

If the x-axis used the same dimension as the y-axis, it'd look a LOT flatter and MUCH more benign.

Have fun riding!

cheers,
Johnny