It does seem that PD have something against copying others ideas, and like to stick to their own guns instead. That's very admirable, but sometimes you have to just suck it up and admit other people have come up with better ideas and copy them. Heck, Forza did it in a huge way to start with by basically copying the whole of the GT gameplay idea, but now they've added their own unique ideas PD need to really look at some of them and use them as inspriation.
They've clearly already taken inspiration from Forza's PI system for their own PP system, so hopefully they will follow with other things. Otherwise Forza is going to keep innovating and moving forward and PD are going to be left in the stone ages with their own ways.
It works both ways though, Forza devs still need to look at how GT are doing some things and copy/improve.