Why are there so many exit signs in my hotel?

The hallway of the Seattle hotel at which we stayed. 

The possibilities are:

1. Someone over-ordered exit signs and green signs are very hard to return
2. Green is the colour of the Emerald City so half of them were put at Munchkin eye level
3. The lower ones are for cases where you have to crawl under the smoke.
4. That's oddly specific, as if they have learned from their mistakes. I'm no longer comfortable staying at this hotel