In the case of federal government, over the last several decades, and in particular over the last 15-20 years, most of the people we have elected to carry out our wishes have been co-opted by the power-hungry, manipulative Washington political machine.
That machine wants to exert more and more control over us, and an integral part of that process is collecting more and more information about our comings and goings, our purchases, our habits, our medical status, etc. Of course, government tells us that it needs such information to do its job--taking care of us.
The assertion that we shouldn't mind having the government track our lives as long as we are doing nothing wrong or have nothing to hide is naive. Government continuously adds to the list of things that are illegal, even felonious, sometimes without fanfare. At the same time, it expands the ways in which it purchases the loyalty of more and more voters with what it benignly labels "social programs."
The systems for knowing everything about us have been and are being put into operation so government can use personal, formerly private information to at first gently prod us and eventually threaten us, thus to ultimately control us. RKBA is the ultimate obstacle to this process, and the Founders knew it.
That's why believers in the increasing power of government desperately want to kill RKBA.