Unfortunately almost all parents think that they are a very GOOD thing.
So who is right?
My view is that although they do not give a perfect comparison of schools, as they can be fiddled slightly (by concentrating the best teachers and resources on the c/d borderline kids and entering pupils for even easier GCSE 'equivalents', the bottom line is that they are better than no comparison at all. After all most parents are only comparing a small number of potential schools in a limited area, who will use similar tricks to boost their results and if one school is significantly better than another then this will show up.
One of the reasons that we are no longer taken seriously as a profession is that we refuse to accept any form of accountability. The League Tables could be improved and we should be the ones pointing out exactly how this could be done, rather than simply rejecting any form of comparison out of hand.