Confusing Youtube ruling

As technology progress rapidly, the tensions between emerging internet business operators and the traditional copyright owners have become grown. At first glance, I thought YOUTUBE case was similar to the Napster(2001), Aimster(2003) and Grokster(2005) which did not pass the safe harbor provision under section 512 of the DMCA 1998. Napster was liable for the copyright infringement because it had actual knowledge of direct infringement and the ability to control the infringement such as removing the copyrighted material. Aimster also was not covered by the protection of the safe harbour of the DMCA, because its technology has substantial infringing use and it did not make effort to terminate or reduce the repeated infringing use. Likewise, Grokster also did not jump the hurdle of the copyright infringement by ‘inducement test’.

Accordingly, I thought Youtube would have the same result with above cases without hesitancy. In my opinion, it has actual knowledge internet users upload and download copyrighted work. Notwithstanding taking more strong precautionary actions to prevent user’s infringement, it hasn’t. Besides, it gains monetary benefits from advertising which seemed to me as exceeding eligibility of safe harbor provision.
However, it was concluded as sheltering from the copyright infringement liability because Youtube followed the DMCA rule as notice and taking down. I don’t mean that the Youtube should be liable for the copyright infringement. At least, I believe the majority of the Youtube video was generated by users’ own creativity(UGC) which does not consist of the copyright infringement. Also, I don’t want to devaluate the positive function of the Youtube as such facilitating new technology innovation and social functions to build networking and sharing information.

However, my confusion seems to be caused by there might be something to miss in applying the DMCA rule consistantly. Isn’t there any way to satisfy both IP technology innovator and the copyright holder? How about remanding the DMCA with more clear line? Is it impossible to establish thorough filtering system to block distributing copyrighted work in advance? How about changing Youtube service to subscribed bases and then distribute the revenue to copyright holders?