If they hadn't used stock buybacks, they would have issued dividends, and we would be in the same situation.
The idea a business might be prepared to weather cyclical downturns doesn't seem that unusual to me? Seems more like competent management?
[1] https://www.cnbc.com/2019/11/07/microsoft-apple-and-alphabet...
I don't necessarily think that companies should be banned from ever doing stack buybacks when they have sufficient cash (for some definition of sufficient), but allowing companies to take on debt to do stock buybacks seems asinine, both on the part of the company doing the buyback, and the creditor lending them the money to do it.
Any company doing so should be the last one to receive a public bailout; so maybe regulations should be targeted to industries deemed too critical to fail, such as airlines.