Stock buybacks are substantially equivalent to dividends. You issue a dividend when you have nothing to invest in that will develop shareholder value. Buybacks work the same way. You have a stock of capital, or a great borrowing opportunity, and nothing to do with it.

Most companies always have another idea to do a new thing, that might induce growth. WW did not. WW has been in trouble for decades, because their business model pre-supposes consumers are too stupid to use a search engine. (Does "weight watchers" work? No. No it doesn't.)

The debt-for-buyback swap is a symptom, not a cause. Management had nowhere to go, no vision for growth, and when you are out of ideas and you are offered an attractive loan, you do a buyback.