Excessive similarity or dissimilarity, leading to inappropriateness or poor quality of the exterior appearance of buildings and structures erected in any area of the town, adversely affects such beauty and symmetry, as well as the desirability, of surrounding properties and neighborhood areas for permitted land uses. By so doing, such conditions impair the benefits of occupancy of existing properties, as well as the stability and value of both improved and unimproved properties. As a result, they prevent the most appropriate development and use of such and cause degeneration of property, with attendant deterioration of conditions affecting the health, safety and general welfare of the community, and, further, they destroy the proper relationship between the taxable value of real property and the cost of municipal services provided therefor in such areas.