Open source projects that are not GPL'd cannot adopt the code; it's meant to be linked into the kernel, and so distribution will trigger the viral licensing clause covering the entirety of the kernel.

For example, there are a myriad of products based on BSD; everything from pfSense at the low-end, the Juniper routers at the high-end.

If the goal is to make money by licensing the code for non-GPLv2 use, then the GPL might make sense, if you're unconcerned about limiting market adoption by precluding integration by non-GPL products.