When General Motors announced it was cutting up to 14,000 jobs and idling five automotive plants, it justified the massive cuts by citing long-term savings. The cuts would free up $6 billion in cash, for a net savings of $4.5 billion in cash by 2020.

The move will "make General Motors more agile, resilient and profitable" while the economy's still revving, CEO Mary Barra told investors Monday. Wall Street seemed to believe her, with GM's stock rising nearly 5 percent and one analyst on the call congratulating her "on getting in front of the curve here."

But GM hasn't exactly been tightfisted in recent years. The company has spent $10.6 billion since 2015 buying back its own shares, according to filings with the Securities and Exchange Commission. Stock buybacks do nothing for a company's productive capacity. But because buybacks reduce the number of shares on the market and thus make a stock more valuable, they can be popular with many investors as well as senior executives who are paid largely in stock.

Get Breaking News Delivered to Your Inbox

GM is far from the only company to spend money goosing its stock price. This year alone, corporations have announced some $955.6 billion in buybacks, according to TrimTabs Investment Research, and the figure for the whole year could exceed $1 trillion.

But GM started its stock repurchasing program back in 2015, less than six years after a bankruptcy process that cost U.S. taxpayers $11 billion. (The United Auto Workers and a number of politicians have pointed to the bailout in a vow to fight GM's planned cuts, though it's unclear politicians can do anything to change them.)

The company announced $5 billion of buybacks in March 2015, then added another $4 billion later that year. In 2017, it re-upped and announced a further $5 billion in buybacks, $1.6 billion of which have so far taken place.

GM's stock price dipped 2 percent over that time period.

"[T]hat money could have been used in different ways, including investment in older plants. But would that be a good way to use the earnings? Mary Barra thought not," said Mary Lovely, a senior fellow at the Peterson Institute for International Economics. "She decided that the money should be taken out of the company and returned to shareholders. It's really quite a statement about where she thinks the traditional auto sector in the U.S. is headed."

Where it's headed seems to be an SUV-only road, as GM will stop producing most sedans after next year, leaving only the Chevrolet Malibu and Sonic. (A GM spokesperson also noted that the company plans to launch two new Cadillac luxury cars.) The company's difficulty creating a profitable small car that can compete with imports represents another missed opportunity, according to William Lazonick, professor of economics at the University of Massachusetts Lowell.

"If it was simply that 'There's global competition and we can't make cars in the U.S.,' okay." Lazonick said. "But given the extent to which money's been pouring out on things that are useless, including supporting the stock price, I don't think you can make that argument."

He cited the 2015 buybacks as "particularly egregious" because they happened when the economy was weaker and GM was returning to steady profitability. "They could have put that into the people who build their cars," he said.

A company spokesperson did not address the buyback question, but said in a statement to CBS MoneyWatch that GM was "building on the comprehensive strategy laid out in 2015" and that it would "appropriately reinvest in the business, maintain our strong investment grade balance sheet, and return all available free cash flow to our shareholders."

Where else could GM have gotten $4.5 billion? It could have dipped into $6.5 billion in overseas profits, suggested the Institute for Taxation and Economic Policy, a left-leaning research group.

Although the GOP tax law last year made such repatriation easier, Fortune 500 corporations have overwhelmingly opted since its passage to buy back their stock instead of repatriating their cash, according to public data. "This trend flies in the face of the Trump administration's promise that the corporate tax provisions — especially a tax holiday for profits stashed offshore, of which GM appears to have had as much as $6.5 billion — would spur a flood of new domestic investment," ITEP said.

Rachel Layne contributed to this report.