This is your opinion, not everyone shares it, and of those who do, I suspect you'd find radically different views exist on what makes a vibrant or attractive community. If property values and house turnover times are better than average, odds are the people living their feel the place meets their ideas of vibrant and attractive, and they are the only people whose opinion matters, so long as they are breaking no laws.

Again, most gated communities are targeted at seniors, they do not typically want the same things. They probably already owned a normal house, they have decided that they want to move to a place that has been specifically desinged to be quiet and peaceful, it's usually good for their health.

You've tossed out the word ugliness, but this is your opinion and frankly one I suspect has little real examples to justify it, I think you're assuming a lot of things here about the motives and values of people which is not really backed up by reality. Now, DK's hypothetical, so far as it goes, certainly is a tad loaded, but in terms of such places that actual exist in this country, they do not appear to match up to what you are assuming.