My husband and I have been Airbnb guests for a few years, and we just started hosting two months ago. So far, we have had ~10 guest groups, and a maddening, albeit small, issue with two of them: 4 stars for location, putting us at a current average of 4.5 stars. As a guest, I have never given anyone less than 5 stars on location for one reason: I always know the location of the Airbnb beforehand. I make sure that it will fulfill the goals that I want to achieve while I am staying in that particular place. If my main goal is to see the Cristo in Rio and I chose an Airbnb that's far away from the Cristo, that's totally on me as an Airbnb guest!
In our particular situation as hosts, we're seeing a trend. We live in Boulder (Colorado), and guests are motivated to come here for one of three reasons: to visit someone at the University of Colorado, to hike/run/bike the trails, or to go to Pearl Street (downtown). What I'm noticing is that both guests who left 4 stars were here to visit Pearl Street, which is an 8 minute drive from our house. CU and trails are very close to us, so guests who are interested in one of those two things never knock us on location.
I have read defensive responses from Airbnb that claim the "Location" rating will guide potential guests in their decision to stay at a place. But I don't think Airbnb makes it clear what "Location" really means. It is very subjective. For one person, an Airbnb might be in a good location because it's in a safe neighborhood. For another person, it may be in a good location because it's near cafés, restaurants, and the mountains. For the next person, it may be in a crummy location because it's not in the heart of downtown.
Listen, I know that people don't read or do their research, especially when using the "Instant Book" feature. I get that. However, location is the one thing that a guest has an exact idea of before booking. It's impossible to lie about where you are ... Airbnb shows you a map of the area! If the location doesn't appeal to the guest for his or her particular needs for the trip, then they simply should not book the Airbnb. The host should not be penalized for a guest's mistake. If you arrive at my place and it's filthy, not as pictured, or my communication is awful, then that's my fault. But if you arrive and just then realize that you can't step out the door and suddenly you're downtown ... that's on you.
Here's my appeal to Airbnb to get rid of the "Location" rating. There's no way to be objective about it, and the guest has all necessary location information beforehand.