There are many big sites that accept bitcoin but are not related, an example being dell and dish who both accept bitcoin.
But I guess those sites accept Bitcoin as an experiment, but make their living out of fiat money.
The whole point is that when I think about bitcoin, the only people I know who admit to make money out of it are gamblers and speculators.
Small companies like shops are really skeptical and some of them declare to have lost money by accepting bitcoin,
And their final goal is to use bitcoin as a temporary method to increase their fiat money. That is a symptom of failure.
If real and honest work is being exchanged for bitcoin, for me that is a symptom of success.
I think that most companies that rely on bitcoin would be bitcoin based or related at this point in time. I understand what you are saying and I am sure in the future more companies will accept and take bitcoin but with current volatility it is hard for a company to rely on it all the time.