Defense Secretary Philip Hammond, who broke the news of the cuts to Parliament, said there was no getting around the fact that times had changed. Shipbuilding is an increasingly competitive market, particularly in the military sector, where governments are cutting down on procurement costs.
It is simply a "fantasy" to think that Britain's ship builders could experience a renaissance, he said.
The decision to close the Portsmouth yard also reflects the country's fading connection to the sea. The rise of container ships concentrated in a few large ports has decreased the visibility of commerce by sea.
Robert Blyth, a senior curator at the National Maritime Museum in Greenwich, called it "sea blindness."
"We're a very urban population. The major ports have moved away from the major cities. The mass movement of goods that still goes on through shipping is somewhat invisible," he said.
Even so, unlike factories, or call centers or other major employers, shipyard cuts are talked about for a generation, said Guy Anderson, an analyst for Jane's Defence Industry.
He said the shipyards' troubles stemmed from their inability to deal with the fitful nature of the market. Orders for warships provide plenty of work, but only in bursts, followed by long stretches of inactivity for the yards.
"Effectively, the sector is cyclical - often described as feast followed by famine," he said. "The major challenge has always been keeping shipyard workers active and skills alive during periods when there are low orders or lower production rates."
BAE won't be leaving Portsmouth entirely, and will continue maintenance and radar system operations there.
Still, many bemoaned the loss of a dockyard that traces its history to King Henry VII. His son, Henry VIII, paid for the Tudor warship Mary Rose. Portsmouth built the HMS Dreadnought, a battleship used during World War I that was notable for its "all big gun" main battery. The city paid for being a naval center during World War II, when it was bombed heavily.
"Portsmouth is so linked to the navy," Blyth said. "It does break a sort of long tradition."