The fact they were not shows they're terrible at sustaining a long-term successful business, and they deserve to fail. Only well run future-looking companies will survive something like this. i.e. all those companies in Japan that have been around for eons.
Most companies would be correctly criticized for hoarding cash. Companies can also be sued for keeping too much cash on hand, as for example, is the case with apple.
In practical terms, they didn’t hoard much and what they did was invested in financial instruments, so it was still increasing money velocity in the economy.
Which is what most people mean when they say "cash" in the context of company financials. As long as it's reasonably liquid, I consider it "cash". Investing in the company, on the other hand, is not liquid (e.g. hiring, buying planes, etc).
Sounds like there should be a new law to prevent this kind of thing. As the other poster pointed out, Japanese companies that have been around for eons don't seem to have this problem, so it's quite likely they keep lots of cash in savings to weather major downturns in business.
Japanese companies that have lasted a long time are family companies that don't have obligations to the public. The government mandates that public company boards act in best interest of the public shareholders, which means distributing their profits or using them to make money.