When will people spend BTC as easily as fiat , not seeing it as an investment opportunity but a better currency for them to use ? Most of my friends that I have currently told about Bitcoin are most intrigued by its rapid rate of growth and not its outstanding features as a currency. They don't really care that it is free from government control , but are more focused on the fact that it has risen xy%
Until it becomes a generally accepted legal tender. Economics textbooks define a legal tender as a medium of payment recognised by a legal system to be valid for meeting financial obligations. Paper currency and coins are common forms of legal tender across countries.
If Bitcoin can be generally accepted by the world government, then, people will be comfortable spending it like FIAT currencies.