My question is why do think bitcoin is deadly or scary??

What I think is it's a very potential thing which will make great benefits in future if it gets at it's top destination. There are peoples who sees its potentials and peoples who sees as a destruction of current currency, specially the governments and banks, and there are reasons behind it which are misunderstandings. Governments and banks have started to understand the potentials and values and advantages of bitcoin, though the understanding speed is slow but it's happening. Which is a good sign. It means it's not scary or deadly at all. And of course our grandchildren will talk about it in future, but about the business they will do with bitcoin.