It seems to me that
"Real" pilots would like the PPL syllabus to include full spins, side slipping, barrel rolls, etc (but surely one can do additional training for aerobatics)
Taildragger pilots would like every PPL to have taildragger training, so they can fully appreciate the fun of flying a taildragger (but surely you can get differences training for that)
Pilots who got into flying to go places (myself) want the PPL syllabus to include much better nav training, GPS, the IMC Rating, as well as wanting instructors that actually fly IFR for real, as well as being able to rent planes that aren't falling to bits, etc (no likely solution to this one; you have to do the IMCR / IR and then buy a decent plane)
ATCOs, judging from their regular moaning here and everywhere else anyone is likely to read it, would like people to (somehow) know where they are when they are flying. I suppose they want better nav training (but how much more certain of position can Mr Average Pilot get when all he's been taught is a stopwatch and a piece of string?). Nothing will change on this front until dead reckoning is abandoned or supplemented with something better.
None of these groups are going to get what they want, because the 45hr-min PPL syllabus is far too short to teach someone all this stuff, and any changes have to be internationally agreed. In 45hrs, you can learn to just about takeoff, fly level, and land, safely. It's no good complicating things beyond that. And one has to keep the 121.5 people in their jobs - if everybody got a GPS and used it correctly, they would be completely redundant
