coaching -- again

An interview with the toppers of last year's CAT is all about strategy and practice. So the person who has a test-cracking technique and has practised a lot can get 100 percentile. Of course inherent ability has to be there too. This is where the coaching industry scores.
Now this is not a bad thing for CAT since a degree in management means you are going to work for/ start or some business. Here such skills like strategising, juggling with what you have etc is important. So the successful test taker will also make a successful manager. The coaching matches the future career requirements to some extent.
But when it comes to science or research, these are not the most important skills. At a basic level, you cannot even make a curry without planning, but beyond that, science requires other skills. So coaching is fine for CAT, but is it fine for exams like GATE? or even for the JEE? Is coaching developing the kind of skill needed for that particular career? Therefore, should such exams be "coachable"?

This blogpost(thanks to prof Giridhar) is one viewpoint. The engg college entrance exams are perhaps the most coached-for exams-- particularly the EAMCET in AP. Is that why the students learn very little?
Coaching is nothing new. Oxford had its crammers for the various scholarships they had...the cram system is well established there since centuries. Does it produce scholars?