Dibble's First Law of Sociology: Some do; some don't.
Accentuating the positive is cold comfort. Tenth-century Rome hosted the development of Gregorian chant and papal charters for the first universities. Focusing on those positive developments doesn't change the fact that Rome was a step or two above a cow town compared to contemporary Constantinople or, better yet, first-century Rome.
Of course Detroit has nice places and nice people. I saw examples of that and my brothers have seen more. The reason why so many people focus on the ruin porn is that Detroit has so much more of it than most cities of its size. Speaking of size, Detroit has lost more than half of its population in forty years. Satellite photos reveal that the city is steadily returning to wilderness. This happened to the premier heavy industrial city of what was supposed to be the wealthiest and most powerful nation on Earth. This is a flipping travesty!
Similar decline happened to other American cities at the same time. Philadelphia. Saint Louis. Newark. The South Side of Chicago. Parts of San Francisco and Los Angeles. It nearly happened to the entirety of New York. Let's face it, these cities were more livable when they were run by ethnic machine politics staffed by people who squeaked through third-tier parochial colleges.
What makes this ruin porn all the more infuriating -- and disturbing -- is that it started when the cool people with the right ideas from the Ivy League schools stepped in. This is what makes us really uncomfortable. We know that it's "incorrect" to say it. The urban renewal and racial integration policies that were ostensibly supposed to improve these cities have utterly and ignominiously failed.