The flip side is that YouTube responds to even frivolous DMCA complaints in a darn hurry. The long and short of YouTube is the DMCA: as long as there are not a pile of Viacom like lawsuits (which argues pretty what you argue) they will continue to exist in the space between the DMCA safe harbor and the complaint.
If you really feel that using the safe harbor in this manner is abuse (and avoiding becoming an editor is a great excuse for doing so; otherwise they become liable for all content) then throw in with companies like Viacom and sue them for all the content they used of yours without permission. I’m not aware of any though, so I guess you will have to simply stare at them with righteous indignation for the legal hack they have performed.
The sad thing is that if Viacom has a full victory in the courts, the DMCA safe harbor will become a thing of the past and we will all be liable for anything our users post. This will lead to most sites prohibiting user contributions. So, I’m hoping that Viacom loses or wins on a very narrow ruling that avoids that outcome.