The thing is that metro is there, and it is going to be there. If you have a serious problem with it, the onus is on you to change the behavior of your PC to not use the metro apps. I don't mind using the metro PDF viewer at all. But I don't like to double-click on images in the Windows shell and launching the metro picture viewer. To me, that is jarring and a little annoying. Therefore, I set the default program for all image files to be the old Windows image viewer. It is just something you need to set the first time on a file by file basis, then you're set.
I mean, there has to be a default. If you default it to the desktop version, then you're "backtracking on the metro vision". If you default it to the metro app, then they are "forcing metro upon you". There's really no way for it to be perfect out of the box for everyone.