Because you asked, even though it's now way off-topic for this thread (and I will not respond further):
Because the text of 2A does not indicate that the right is contingent upon participation in a militia (and indeed 10 USC 246[1] legally defines the US militia as all able-bodied male citizens of ages 17 to 44 inclusive, as well as all female citizens who are members of the National Guard, even if it did), as 2A actually specifies RKBA as a right of the people (not "people of the militia", just "people").