The single examination dream – what went wrong?

TOI today reports on what went wrong w the plan to introduce a single entrance exam...."Since June, it's been chaos. The single exam dream went awry. Students couldn't crack the normalization formula till the JEE (Main) scores came. Those with high JEE (Main) marks and reasonably high Class XII scores - by today's standard 90% isn't a good enough Boards score - found their ranks had slipped. Litigations began."