its a reason but not major at all , the major issue its all about lack of good knowledge and experience.
most of the people keep short term mentality, as a result they try to bring something more with very rapidly but Forex and success is a long term approach.
One of the most strongest reasons certainly. Emotions turn out to be a huge challenge for traders only those who are able to control them can prove to be successful eventually.
One more reason : when do you trade forex? If you traded forex in 2008, you could trade forex blindfolded. Now you can't.