coarse
笨 centers on roughness or lack of refinement: something coarse, crude, or unpolished.
笨 combines 竹 (bamboo) with 本 (root/origin). The exact historical development is uncertain, but it likely originally referred to the coarse inner layer of bamboo.
Bamboo 竹 over a root 本: picture the rough, fibrous inner surface of bamboo, which is coarse to the touch.
For ホン, imagine a coarse bamboo book (本, ほん) whose pages are rough and unpolished: 本 -> ホン, and the book feels coarse.
crude