Check this map instead
http://i.imgur.com/QwvATt1.jpg
The authors already did that analysis, but they incorporated population, area, age, income and perception of safety into a statistical model used to predict violent crimes.
It is important to go beyond the bivariate case here. Comparing streetscore to crime is too simple to be meaningful if other co-variates are not taken into account. For the full description (http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjourna...)
I think you fail to understand the point. The point is not too replace a map of crime, but to help develop variables that can help explain the location of crime. Look at what they did in their 2013 paper (http://pulse.media.mit.edu/papers/) that is exactly that.
The problem they are trying to solve is that there are no good measures of perception to evaluate whether the environment affects crime or not. This is an old question for which there has been much research, as it is explained in the point 7 of their FAQ. http://streetscore.media.mit.edu/faq.html
If you look at the 2013 paper from this same group you will find that this is exactly what they did (http://pulse.media.mit.edu/papers/).
Even further, they used geospatial statistics techniques to control for the effects of the income, area, and population in an area, and hence, developed a model that incorporated not only perception, but also demographics, when predicting the location of homicides.
It is important to go beyond the bivariate case here. Comparing streetscore to crime is too simple to be meaningful if other co-variates are not taken into account. For the full description (http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjourna...)