Bernie is losing because his vision is too narrow. He is attacking small groups and appeasing the wrong group of people, the people that will vote democrat no matter.
I'm okay with that though, he can keep campaigning in irrelevant states (sorry, but let's be real) while Hillary increases her chances in states heavy in population and delegates. When it comes to the general election, Hillary will win all the democratic states that she and Bernie have won and will pose a threat in swing states and possibly Republican states, especially considering her competition lol.