To protect and conserve present and future property values and the tax base through the promotion of harmonious and enduring neighborhoods, by preventing the construction of inappropriately large or inappropriately small structures in established districts, by preventing monotonous and unsightly uniformity of building development or unsightly structures of incongruous or inappropriate form that might tend to depress surrounding property values, all of which purposes are hereby declared to be legitimate and proper public objectives, clearly in the public interest and in harmony with the broad purposes enumerated in the Village Law.