Why would anyone want a cl M2 license in CA?

The cl M2 license allows you to operate motorized bicycles of 150cc or less; the M1 allows this, and also allows you to drive any motorized cycle of any size. To get either, you need to go through the same process (paperwork, a road test OR MSF safety course). Why would anyone want to just get the M2 when for the same amount of work you can get an M1?