It's a combination of that and status. Wealthy families would build tall towers as a way to protect themselves: if you think you're at risk of getting wacked by

It's a combination of that and status. Wealthy families would build tall towers as a way to protect themselves: if you think you're at risk of getting wacked by a disgruntled competitor, you take to live in your tower for a few months, where nobody can sneak in. From that, it became a competition to show off the biggest pen1$-- sorry, tower; and then someone probably figured that the benefit of height could be used for the common good as well, installing city guards on the tallest towers.