Balanced lines are less susceptible to picking up hum fields in very long runs. In recording studios, there can be 50-100 feet+ cable runs, not likely to be used in a home. Also, studios have lots more equipment radiating EM fields.
Balanced lines became fashionable in home audio because it could be marketed it as "professional", and the audio rags picked up on it, espousing their usual "imaginative" attributes, which were absorbed into the psyches of their true believer dittoheads.
To have a balanced line, there has to be double the output and input circuit components, increasing circuit complexity. Interestingly, some of the same people who proclaim the sonic virtues of balanced lines, also are convinced of the sonic wonders (and circuit theory) of "pure and simple" SETs, which are the exact opposite of balanced circuits...