Why? Well...since Zayn split with the group One Direction, they've been on the rocks, whether the media said so or not...and now Harry is going his own way...with his new solo debut tour.
Since this was a group created out of necessity, not out of true wish, it was only a matter of time since it completely fell apart.
The fear with a solo career is that if you're not talented enough - it'll come back to haunt you one way or another. Fans will see the light sooner or later. Hopefully, Harry is as brilliant and capable as he thinks he is!
Now - the only thing left for the fans to do is to split up into groups following the members as they pursue their solo careers and find out once and for all who was that one member who was indeed the most talented.