At that time, Oregon had a really harsh territory, so not many business owners wanted to try their luck in the territory.
The settlers and trappers were tough enough to actually transform that harsh environment into decent living environment, which paved the way for long-term Oregon.
United States and the British Empire saw this area to be very lucrative for fur business. So, they both agree to set up joint ownership in Oregon and let the citizens from both countries to acquire land on this territory and open new businesses.