Eh, it’s more-commonly used globally than Washington-the-state, which is often called “Washington State” to avoid ambiguity.

EDIT: Though it does look like we did try to disambiguate the two, apparently not very effectively:

https://en.wikipedia.org/wiki/Washington_(state)

Washington was named after President George Washington by an act of the United States Congress during the creation of Washington Territory in 1853; the territory was to be named “Columbia”, for the Columbia River and the Columbia District, but Kentucky representative Richard H. Stanton found the name too similar to the District of Columbia (the national capital, itself containing the city of Washington), and proposed naming the new territory after President Washington.

Then apparently Washington, DC had a go at swiping the name:

Confusion between the state of Washington and the city of Washington, D.C., led to renaming proposals during the statehood process for Washington in 1889, including David Dudley Field II’s suggestion to name the new state “Tacoma”; these proposals failed to garner support. Washington, D.C.'s, own statehood movement in the 21st century has included a proposal to use the name “State of Washington, Douglass Commonwealth”, which would conflict with the current state of Washington. Residents of Washington (known as “Washingtonians”) and the Pacific Northwest simply refer to the state as “Washington”, and the nation’s capital “Washington, D.C.”, “the other Washington”, or simply “D.C.”