Porsche has never followed trends. The key is on the left side...
I actually think that the SMG sequential directions are counter-intuitive. So what if the 11 PDK uses a different convention? Are you going to be confused?

The steering wheel shifters are another convention. these are not tip buttons. These are paddles that you push to upshift or pull (push from the back) to downshift. And again it is just a learning acquired process, like anything. Again PAG does not follow trends, mostly sets their own, and I actually like that.

Notice that the steering wheel seems to have a flat portion at the bottom?