That is like explaining that the reason for fertility decline is Americans just prefer to not have babies.
A hundred years of direct and indirect subsidy of auto-dependency, from all levels of government, especially federal, with much of that financed via public debt obligations laid upon future generations that have led to hundreds of millions of people buying cars, generally with more debt, and buying houses designed for cars (as codes and zoning requires), also with more debt, and when a business tries to paddle against that current and fails, you explain its failure by saying Americans simply prefer auto-dependency.