The simple fact is that bitcoin isn't widely accepted. The consumers need something to spend it on. The sellers will not accept it unless there's a big demand. We're stuck
That is one fact. But there are still a lot more. Knowledge and some bad past of bitcoin through the creation if media and the government are one more. Lazy people dont want to listen to a person who will explain thoroughly what bitcoin is. That is another problem.
easier to use cash and credit cards for everyday shopping, and I doubt it will change. Cash can always be used without internet, bitcoin not. Credit cards and paypal confirmations are instant, whereas for bitcoin it is about 10 min, but usually more.
Also people get their salaries with fiat or directly to their bank.