i also don't think that bitcoin could change fiat, but actually i think that bitcoin can be alternative currency in near future, we just have wait for that
Bitcoin won't ever take fiat any time soon but we cannot know as anything can happen. I will stand by my point that fiat will always be there. But bitcoin will be up there with it. Fiat has already set it's stance into the world while bitocin is just coming up. So I will wait a bit before judging anything like you

In anyway I look at the situation, bitcoin could never replace fiat, that's for sure, there is no sign that it will be recognize by the government as a money... That I think is the hindrance, if government couldn't even endorse bitcoin there is no way that it will replace fiat.
You have a point its up to government if they would replace fiat to bitcoin. Its always their decision on making up things but i think it would really take sometime when it fully recognize bitcoin on a certain country since most of the people only knows paper currency on our everyday living.