Development follows transportation, and since the main method of travel in the U.S. has been rubber tires and individual vehicles for the last 80 years, naturally a train can't service a whole suburb or exurb efficiently.
Trains have trouble in the U.S. because the technology allows--even requires-- central planning and authority on an active, everyday basis. If the transportation department goes on strike, we in cars keep driving. Not so for trains. Also it's not a fair fight to have a public decentralized asphalt road system compete with a highly regulated centralized private rail system. It's not a pure technology vs. technology battle-- the political aspects dominate.
Trains have trouble in the U.S. because the technology allows--even requires-- central planning and authority on an active, everyday basis. If the transportation department goes on strike, we in cars keep driving. Not so for trains. Also it's not a fair fight to have a public decentralized asphalt road system compete with a highly regulated centralized private rail system. It's not a pure technology vs. technology battle-- the political aspects dominate.