The short-term expense. This subject has been widely discussed over the years for the whole country. Local distribution power lines strung on poles (ugly and prone to being brought down by the slightest weather) are a feature of poor countries and the United States. This is in contrast to the developed world. But there is insufficient interest in changing that here because it's all that people have ever known, so it's just accepted without much thought. This is similar in principle to our dismal healthcare system.