Of course he still has plenty of fans, but it's true the tide does seem to be turning against him somewhat. There seem to be several reasons for this.

One reason is probably just what they call 'tall poppy syndrome'. Anyone who gets a lot of fame, praise and attention can expect a backlash sooner or later - so part of what's happening to Justin Bieber is just what happens to most celebrities at some point.

Another is that when you get someone who is not just famous but a kind of cult - eg there was a point when it almost seemed like all teenage girls 'had' to like him just to fit in - again, when the first hysteria has passed you get a lot of people thinking 'actually I never liked him/her anyway'. Then they almost exaggerate how much they dislike the person!

Finally, he really isn't everyone's style and probably hasn't deserved all the attention he's got. This isn't his fault, but it is annoying to have someone in your face all the time who you would rather not see - and he can be quite annoying because he seems so pleased with himself, which probably puts people off too.