Because they are scared that is main reason ,they see that bitcoin becomed ilegall in some countries and also bitcoin is good for normal pupils so they think that our coutries will not allow that cryptocurrency but that is wrong some countries will not support but most will support bitcoin but also some countries will have own unique nathional cryptocurrency like Sweden and Norway.Bitcoin can die only with bad laws in most world countries which dont give to pupil access to bitcoin and also if new bitcoin cryptocurrency enemy coin come better than bitcoin and also if something come what is even better than every cryptocurrency.
I also think that the government - is the main enemy of Bitcoin. Many countries indicate that Bitcoin is dangerous. Tie the two concepts - Bitcoin and terrorism. All this is bad for the popularization of Bitcoin. Therefore, people do not believe in it
If I look at my country I feel that my government is not enemy to bitcoin because my country is acting neutral to the decision of bitcoin and when it come to the supporters of bitcoin I see that government are more polite with them and often help them in their projects for the promotion of bitcoin.