AND helps them avoid a liability to stockholders should the stock price take a turn for the worse.
You might be asking yourself why a company would issue shares with no par value. Corporations do this because it helps them avoid a liability to stockholders should the stock price take a turn for the worse. For example, if a stock was trading at $5 per share and the par value on the stock was $10, theoretically, the company would have a $5-per-share liability.