I think it is fair, because they're preparing them right from the start, not changing the system halfway through their GCSEs. To be honest, I'd have rather done those GCSEs, because even a 7 or 8 on those exams will be regarded as pretty high. I think it's a genuine shame that many people who sit GCSEs and get A*s are academically backward compared to international standards- doing the tougher GCSEs means that you will work harder to get the grades that are more difficult to achieve.
However, I do wish on the other hand, that the government had not changed the system for us part-way through the GCSE course (in the case of science particularly) from modular to linear. Although this prepares us better, it is unfair because we had already started the course. Changes should take place at least a year or two before a student starts a GCSE course, to ensure that they are prepared for the rigours of it.