Sources who were at the meeting tell TMZ ... Oprah explained that OWN had a duty to the board of directors to justify how much the network was spending, in light of anemic ratings and problems with advertisers.

Oprah said the fiscal year for OWN ends on March 31, and she had to get OWN's financial house in order before April 1 -- or else the entire network would be in jeopardy.

Oprah said cutting staff was essential in harnessing the cost of running the network.

But here's the good news for the 30 people who lost their jobs ... Oprah is paying some serious severance ... one person tells us the packages were "extremely generous." We're told everyone got at least several weeks of pay and some people are getting paid for the duration of their contracts.