It's very hard to avoid this. It's mostly a combination of railway noise, throughput of a large number of people who are only travelling through, opportunities for pickpockets and beggars, and historically of soot and air pollution by steam engines, which makes these areas unattractive to live in.

And it is not for lack of trying. City planners since at least the 1850ies have been trying to improve the areas surrounding large train stations.