Why does Congress ignore the Constitution in the District of Columbia?

According to Wikipedia

The signing of the Residence Act on July 16, 1790, approved the creation of a capital district located along the Potomac River on the country's East Coast. The U.S. Constitution provided for a federal district under the exclusive jurisdiction of the Congress and the District is therefore not a part of any state. The states of Maryland and Virginia each donated land to form the federal district, which included the pre-existing settlements of Georgetown and Alexandria. Named in honor of President George Washington, the City of Washington was founded in 1791 to serve as the new national capital. In 1846, Congress returned the land originally ceded by Virginia; in 1871, it created a single municipal government for the remaining portion of the District.

Most people understand that portion of The Districts history. However, most people don't know about this little bullet mark in Article One, Section 8 of the Constitution

To exercise exclusive Legislation in all Cases whatsoever, over such District (not exceeding ten Miles square) as may, by Cession of particular States, and the Acceptance of Congress, become the Seat of the Government of the United States, and to exercise like Authority over all Places purchased by the Consent of the Legislature of the State in which the Same shall be, for the Erection of Forts, Magazines, Arsenals, dock-Yards, and other needful Buildings;

Congress, by law, has the ability to overrule ANY laws created in The District. The District is neither a state nor a city, but a recognized Federal area. Congress did maintain much control of The District up until 1973:

The District of Columbia Home Rule Act is a United States federal law passed on December 24, 1973 which devolved certain congressional powers of the District of Columbia to local government, furthering District of Columbia home rule. In particular, it includes the District Charter (also called the Home Rule Charter), which provides for an elected mayor and the Council of the District of Columbia. The council is composed of a chairman elected at large and twelve members, four of whom are elected at large, and one from each of the District's eight wards. Council members are elected to four-year terms.

Under the "Home Rule" government, Congress reviews all legislation passed by the council before it can become law and retains authority over the District's budget. Also, the president appoints the District's judges, and the District still has no voting representation in Congress.

It should be noted, that any law that Congress passes, another session of Congress can remove. At any point, Congress can take full control back over of The District and fix any laws created by the council.

So, why am I writing about this? I am writing about this because of the recent shooting of Congressional representatives as they were practicing for a charity baseball game. Because the House Whip was present, there was a security detail at the ball field and the only reason more lives weren't endangered. Immediately after Rep. Thomas Massie of Kentucky announced he would introduce a bill that would recognize out-of-state concealed carry permits in the District of Columbia. While I applaud Rep. Massie for trying to get concealed carry reciprocity in D.C., I think there is an easier way for him to do this, that would change things across the entire country.

Currently there are 10 states that have some form of Constitutional carry. The laws basically state, that as long as you have a permit for a gun, then by the 2nd Amendment of the Constitution, you are allowed to carry it either openly or concealed. This isn't a radical idea and almost touches on being common sense. If you can pass the laws to get a gun, why do you have to limit how you can carry that gun.

Rep. Massie, could instead, require that D.C. drop any laws prohibiting concealed carry based on the 2nd Amendment. If the 10 states have been able to pass laws allowing for Constitutional carry, then there must not be any objection by the Supreme Court. In fact, the Supreme Court has already ruled in District of Columbia v. Heller, that the Federal government cannot restrict people from owning guns.

I believe, that if Congress made D.C. recognize Constitutional carry, then other states trying to pass Constitutional carry would have an easier time and those that do not allow reciprocity will have to rethink their laws.