Why did people love Lindsay Lohan and Hilary Duff when they were 14 but hate Bieber and Rebecca Black now?

Lindsay and Hilary were teen Disney idols for girls. All the kids were into Hilary Duff. Now everyone thinks Justin Bieber is annoying because of his horrible obsessive fans and the fact that he's everywhere, I don't even like him but I just want to say, I'M SICK OF PEOPLE SAYING HE'S UNTALENTED, HE IS VERY TALENTED, HE STARTED OFF POSTING VIDEOS ON YOUTUBE AND THEN PEOPLE FOUND HIM AND HE HAD THOUSANDS OF SUBSCRIBERS BEFORE HE EVEN GOT FAMOUS.