Those who sell bitcoin in a high price they're really make bitcoin a success business. You need to much skilled to make it a business success. Those who lost their money because of low price of bitcoin they don't take it as a business success.
But I really agree that bitcoin is a business success.
I think If you have big capital you can save Bitcoin and use your fiat currency to re-supply your business. Then when the Bitcoin price increases, you can sell the BTC to earn additional income. It is up to your strategy on how you will be very profitable in reaching the business with Bitcoin as a way of payment.
It depends on what you offer or sell. If you sell items that are in demand then a big profit can be seen. Also note also the volatility of Bitcoin.