Reservations (SC/ST) - why are they justified
People advocating res. based on economic condition are missing the reason of introducing it. One entire section of society has been, for centuries, being deprived of, among a big list, education - as is evident from our history, and this quote ("yadi veda ka ek shabd bhi koi shoodra sun le to usko kaanon mein pighla seesa daal dena chahiye") from one of our ancient sculptures.
As a result of the above, and also as rightly pointed out in many of the anti-reservation comments below, this section of society is condemned with a lot lower average IQ than rest (I m talking only about avarage IQ, exceptions are there everywhere). Unless the govt. gives them some push in form of reservation, these sections may be continue to remain where they have been living for centuries, occupying the lowest rung of the society.
You may ask me - why should a upper caste teenager, who otherwise could have got into IIT if not for reservation, pay the price for a crime that ancient generations of his (or of his caste) committed ...
Definitely, I agree - it does not make sense.
But on the other hand, why should SC/ST teenagers, who would have had same avarage IQ as their upper caste counterparts if not for this centuries of exploitation and deprivation, pay the price either.

If u go with a sense of medivial justice, where eye for eye and blood for blood was the rule, all upper castes will have to be deprived of, forget everything else, education itself for generations (as many as those of SC/STs which were deprived of it), and then only this historic wrong would get corrected.

Off course, no sane person should subscribe to the above view and thankfully - nobody does.
I mentioned it here so that we, the so called upper castes should realize, that reservation is the least that can be done to undo that historic wrong done with those sections.

I also believe that reservation is bad, but it is the least bad thing available out there. And I also agree that as suggested in many of the comments, reservation implementation flaws should be identified and corrected (i.e. after 3 generations availing reservation, no more reservations in that tree, having relevant cut-off marks, etc etc)