Not to downplay it or anything, but Bethesda still regularly release patches (via Steam) for Skyrim and might keep continue to do so, unlike Oblivion. Wouldn't it be an overkill to create unofficial patch while the official patch keep coming?
Edit:
While at it, you might want to take a look at Louis Letrush bug:
http://www.abload.de/img/tesv_2012_01_31_16_48khozu.jpg
http://i.imgur.com/eHFKO.jpg
http://cloud.steampowered.com/ugc/649876122724895024/80655B52C39D7452617E6AB198DB39F7AC76F289/
1. Bethesda can use the same fixes in unofficial patch for their official patches
2. There is no way to know which bugs will fix bethesda and wich ones not.
3. Not all the fixes bethesda actually makes works 100% flawlessly.
4. Bethesda fixes are often hard coded, while USKP approach is to include the source code of the scripts.
5. People fixing bugs, tend to learn and then share which modding methods could lead to problematic mods. Better to know what you need to avoid.
Those are in my opinion five solid reasons to want a USKP while there is no reason to not want it.