First, lets examine the purpose and function function of the bill of rights itself, rather than any amendment.
What is the bill of rights, and what is its purpose? The bill of rights is a list of restrictions on government. The purpose of those restrictions, is to PROTECT rights.
I'll now cite evidence in support of that.
First, the preamble to the bill of rights:
THE Conventions of a number of the States having at the time of their adopting the Constitution, expressed a desire, in order to prevent misconstruction or abuse of its powers, that further declaratory and restrictive clauses should be added: And as extending the ground of public confidence in the Government, will best insure the beneficent ends of its institution
http://billofrights.org The framers felt government needed some declaratory and restrictive clauses, so that government would not misconstrue or abuse its powers. They wrote those declaratory and restrictive clauses down, and passed them into the law of the land, which we call the bill of rights:
Now, lets examine some amendments:
Amendment 1 says "congress shall make no law", and clearly congress is government.
Amendment 3 says "No Soldier shall, in time of peace be quartered in any house, without the consent of the Owner, nor in time of war, but in a manner to be prescribed by law."
Whos soldier? The governments.
Amendment 4 says "The right of the people to be secure in their persons...shall not be violated..."
Shall not be violated by whom? Governent.
Amendment 5 says "No person shall be held to answer for a capital, or otherwise infamous crime unless on a presentment or indictment of a Grand Jury..."
Held to answer by whom? Government.
Do you see the trend here?
Now lets look at amendment 2 :
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed"
Shall not be infringed by whom? Government. Just like the other amendments. Why? Because a well regulated militia is necessary to the security of a free state.
The function of the document and the amendments it contains, is strictly to restrain government. Nothing more. Reading a part of the document as a restriction on people, is reading the document contrary to its intent, purpose, and function.
Its just that simple.