Just looking at the design -- keychain and all -- this gadget seems to be for casual urban use -- such as when traveling. One can use it to find one's way back to one's car or hotel after a day exploring the town. For that kind of travel use, coordinates are completely unnecessary.
In a city where roads are everywhere, just knowing the direction of your car or hotel is tremendously helpful. OTOH, a gadget that stores just 3 locations will likely be very suboptimal out in the wilds.