The education system

Why is it that since the very beginning of our education system we have made certain limitations and restrictions to it? it seems more like a cast system and not an institution made to literate people rather than categorizing pupil as being superior or inferior. We might not accept this but yes this is a taboo happening every where. Why is it that only children with As and A*s get into good universities and people who have passing yet average grades face similar difficulties as a camel would passing through the eye of a needle.

  To enter most of the universities the students have to pass their admission tests and score a good grade in their board examinations. This tradition often makes me wonder about what reasons are there which make such universities GOOD...and not just good but so good that people actually take tuitions for RS.15 to 25000  to pass the entry test. That is simply stupid! It takes common sense to understand that universities taking the cream are prone to produce good results! it is not their good faculty but the extra ordinary student they pick up who produce good results. Good universities are those who welcome anybody willing to study and then groom and polish them and then help them become smart, intellectuals.
  Selecting extra ordinary students and then producing extra ordinary grades is not any thing commendable.
But welcoming any body willing to study regardless of their grades and then producing remarkable results surely worths appreciation and applause. Lets think rational for once and finish the cast system.