Why were upright pianos constructed then?
For a number of reasons: Many people did not have the means to buy a grand piano. Some people may have had the means, but not the space. It was cheaper to build upright pianos instead of grand pianos. It was not until the 19th century that instruments were produced on a large scale and became accessible to the general public. If there was television back then, there would probably be dozens of programmes called "Piano wars". The competition was enormous!