People downvote you because if this post is similar to previous ones you wrote (I did not read your history), then it contains no argument whatsoever, no line of thoughts, nothing. You say "it is a scam, it is going to crash" without explaining why. For example you seem unaware that Bitcoin is decentralized and what fundamental advantages this gives it over any other currency. So, of course, if you seem uneducated about Bitcoin, people will see no value in your posts and downvote you. I suggest you read the original white paper http://bitcoin.org/bitcoin.pdf as a starting point. (No, this is not sarcasm, I am serious.)