Vote bank. If you remember, a similar pampering was tried by the same party in the 80s which went wrong big time against the Sikhs and while the separatists were crushed, the common innocent people had to bear its brutal results.
The colonial powers from Europe, whether British, French, Portuguese or even trading posts like Dutch and Danes always used this method of 'favouring' one or the other group to make them stand out and thus create divisions.
The ruling party simply took over the job well.
Reservations are a terrible insult to great personalities like Dr. APJ Abdul Kalam who is loved by all Indians (even the most conservative right wing) and respected.
Look at Dr. Tessy Thomas, the first lady to be in-charge of an ICBM project ever. She's where she is because of nothing but pure hard work.
Quota is the biggest bane of our country.
Stupid people who are lazy and don't want to work, don't realize this and ask for reservations.
A road, machine, aircraft etc doesn't know if its builder was Muslim, Christian, Jew, Hindu, Buddhist, Sikh or any other.
It will either succeed in functioning or miserably fail.
That's the truth.
But people will not use their common sense. Piling degrees by joining colleges, institutions etc in QUOTA will get them nowhere.