They never catered to their middle class consituency
The middle class didn't care enough if NDA lost. They didn't go out and vote. For full five years the middle class watched in horror as the 'clerk' didn't care a damn for them in budget after budget. The loot in the form of EPF and other 'Ponzi' schemes(NSC(s) and PPF's and so on which payup their dues after collecting more money--ponzi isn't it) run by government/un-responsive and corrupt bureaucracies continued unabated (it still continues: only now none expects any better from the current government).
Yes the NDA thought it could take them from granted. And they the middle class granted them a well deserved apathy.
The old world politicians amongst the communists and the socialists in India have a single minded agenda "To protect their constituency" 'the poor' by keeping them poor and destroying whatever limited constituency of 'kulaks' has developed despite the Grand Old Party, myriad coalitions and bureaucratic bureaucrats.
Major causes of apathy towards the NDA include
1. Income tax rates not revised. Middle class faced increasing burden of surcharge(s) and falling interest rates on forced contributions to EPF.
2. Telecom Mess: You and I hate it when they know the Telco's fleece you and government takes an official cut in this fleecing called Access Deficit Charge. All when many of us know that its an altogether cheap to setup a Wifi-VOIP based telephony/Internet Access system for the villages if only the government forsakes its silly License Fee Requirement for Unified or whatever licensing for setting up something resembling 'Telephony'.
3. Slow pace of reforms: Most countries want their citizens to move up the value chain. Our bureaucracy(this is what I heard at an e-governance conference) wants to be able to have IT professional's services for real cheap (as compared to today's prices) so that the IT professionals can work in their hives at pittance they offer and work out crappy e-governance desktop style applications written on legacy platforms.
