FlyingForFun has hit the nail on the head. The PPL is a basic license, if you want or need extra capabiltity you will know enough with a PPL to be able to go out and find it. There are many courses available like aero's, EFIS, tail wheel, farm strips etc. and alot of helpful/ knowledgeable pilots/ instructors about that can help with specific things like foreign nav.
Reading this thread it sounds like alot of people want everything they can think of stuck in the PPL.
I do however agree that practical navigation in the PPL should be addressed. There could be better integration in the course of how to obtain relevant NOTAMs, and computer based planning, and perhaps GPS. There could also be some compulsory nav in controlled airspace and filing flight plans.
In fact in the UK you could argue that the IMC be integrated into the PPL since it would be of benefit to all given our weather! This might resolve the problem with PPLs being unable to turn 180 degrees on instruments too. I'll leave it up to you guys to "discuss" whether PPL students should be taught to recover from a spin in IMC though!
Perhaps NAAs should be given some latitude on deciding what relevant "extras" the PPL should include in their specific regions?