Gold is supported by governments and rich individuals who like power and control.

Bitcoin at the moment in the big scheme of things is a small market cap minor distraction to these people.  Should it start to grow to a point where the people above feel threatened or start to loose some power or control they will simply ban Bitcoin.

Some may say you cant ban bitcoin etc. but if the government do decide to ban it a large % of population will cease to use it preventing it becoming mainstream causing the price to crash.

Russia and China are buying gold as quick as they get their hands on it for a reason, the same cant be said for BTC