Why do some towns look like episodes of Hoarders?

My town was just an absolute mess for long time. Starting off late in the game, it was impossible for me to get started with any design ideas until I actually had the buildings. My partners incessant nagging was the only thing that broke my pattern. I was embarrassed to have neighbours! Now I have plenty. I try not to judge the hoarding. It is irritating, but necessary to some degree.