Asserting that the 'degentrification' of neighborhoods is something that is necessarily connected to immigration and at odds with the history of (sub)urban living in the US is absurd.
Americans are not alone in liking both nice, new shiny things and things that are old enough to convey some nostalgic sentiment. When (sub)urban residential areas are no longer 'nice, new, and shiny' and the persons who live in those areas have the means to move to places more desirable, they do so. The results that follows are, more often than not, a replacement of socio-economic demographics. A shift back to middle and upper class residents in that area does not occur unless, at a later time, these houses are now viewed as somehow classic, quaint, etc, as well as viewed as being incredibly cheap to defray both the opportunity costs of perceived safety and the costs of refurbishing.
The thing is, so long as there exist low-income persons in your country, there will exist low-income areas. These areas will have all the characteristics of low-income areas, but they will also always remain as pockets.
Actually, that last assertion is not exactly true. So long as low-income laborers are allowed to work low-income jobs, then low-income areas will always remain as pockets. However, if we try to eradicate low-income laborers and low-income jobs, then over the course of a generation or two most of the US will resemble these low-income areas now because everything will fall apart.
And, at the end of the day, this entire line of argument is irrelevant, because who the **** cares about whether or not something is sightly or unsightly? Oh, wait, idiots care about that ****.