Provided the grades you've mentioned in your sig are true, I don't think your GCSEs are even close to bad. In fact, they're excellent.
But your point is true. Many students don't know which universities they want to go to, and if they need to break their back to get full A*, etc. I can see where universities are coming from. If you have two candidates both with AAAA at AS and A*A*A* predictions, with weeks of work experience and lots of extra reading, how do you choose between the two? You'll have to go back to GCSE where Student A got 10A* 1A and the other got 9A* 2A.