The title represents the question I have been asked ninety billion (or so it seems) times this evening.
The short answer is that there is a military convention in town and everyone has swarmed in to town in an effort to procure a room so they can have a place to come back to after touting their wares at said convention.
The short answer is not being accepted by a majority of the people asking the question so I switched to this answer: "I really don't know."
It's better than asking this one: "Why are YOU here?" (Which I have been known to do on occasion when frustrated with the endless questions.)