Facts: Bad companies have a few flaws such as a grey market, unstable future market share, slowing or aging technology, large debt that is over normal ratios.
Analysis: The Difference is sleeping well at night while you make money. The stock price volatility of both good and bad companies is similar. In fact, good companies have real volatile stock prices due to the uneven growth rates that tend to exaggerate stock price movements. Bad companies tend to have high volatility factored in already where you expect crazy movements. Money can be made from both Good and Bad companies.
The Sleep factor is an unseen factor being a non data point, Both good or bad companies having high volatility, The Sleep factor during high volatility will be decided on whether the company has good fundamentals. Bad Fundamentals will have you on your toes on every movement. Good Fundamentals will allow you to look pass most movements including the ones against you.
Conclusion: Invest in Good companies, sleep well at night.