The West End, when they razed it, was considered to be a run down immigrant enclave, and Scollay Square was one of two downtown areas known for vice. So the reasons for their destruction were very political. They also thought it was a good idea to put an eight lane freeway right through downtown, completely cutting off the North End, which is our Little Italy. The debacle that ensued over the next 40 years led to The Big Dig, what is, to this day, still the country's most expensive public works project.