Why is that?
Most of it is not accessible by road.
Washington has a beautiful coastline too, it’s just difficult to get to. I live near the coast in Washington, yet we always travel to Oregon when we head for the beach..... unless I take a run in our boat. ;>)
Just look at the coast line and the very long drive around the Olympic Mountains and Olympic National Park to get there. Once there, there is nothing more than a few fishing towns and remnants of what used to be a timber industry.
There are also LOTS of very nice places to visit not far from the major population areas.
People in SW Washington usually go to th Oregon Coast where there is lots of stuff to do and is only about 1.5 hours away.
Mostly because it’s kinda inhospitable....and the weather except for a few months of the year is not so great....think, cold, damp, breezy....