Design is very personal. People get upset when discussing their own design or evaluating the design of someone else. But why do people take criticism, whether constructive or not, so personally?
People are generally products of their environment and education. A persons "design" is based on the buildings that they grew up in or around, their experiences from travelling to different areas and cultures, their education from primary on up, and their reading and absorption of reference materials. If a person stays in the same town, on the same street and in the same house, then their design will be centered around that house and environment. They may believe that every house should have a front porch that is 20' from the sidewalk, because that is where their parents sat in a swing and conversed with the neighbors. They may also believe that all houses should have wood ship-lap siding painted a royal blue, because this is the color that they painted their house every fifth summer. Of course, this may also make them want to have brick or hardi-siding that they do not have to paint. Either way, their design is based on what they experience through their lives.
This is the main reason that they take it so personally. When you are stating that the house should not have a porch because people in the area do not sit and talk with their neighbors in a semi-private area, they may get defensive because that is their life.
I never watched the Brady Bunch, but I have come to appreciate a small concept from the show later in my architectural career. Apparently, Mike Brady tended to design his projects around his home. This is comical, but it very relevant to architecture and design. Our design is typically based on what we know and experience, or basically how large of a design vocabulary we have developed. This vocabulary allows us to design using architectural history and the formation of new concepts from the reinterpretation and fusion of old.
Anyone can open their eyes and see the world around them, and by doing so they can increase their design vocabulary. Yes, there are some people that are incredible at understanding the history, communicating their design, and creating new solutions, but not everyone will view their designs as good because they do not have the same design vocabulary as the other designer. This is not bad but just a different interpretation of what we are both looking at.
David R Hoover, NCARB, AIA