The major change that is required (Leeds) is for the festival to be better prepared for the weather. Every festival I have camped at has at some point experienced heavy rain but the site at Leeds was ridiculous at points. At Download this year the moment it started raining there were loads of teams around trying to help avoid serious issues arising from the mud. At Leeds I didn't see any attempts made to try do anything. Even doing stuff as simple as laying straw everywhere defiantly helps make conditions better. When a festival allows people of all ages to attend then they have a responsibility to make sure accessibility is always a priority.
This also extends to the car parks. Leaving on Monday morning we didn't see anyone from the festival helping out in the car park. Under normal conditions this wouldn't be too bad but parts of the car park were just a disaster.