It is immature to compare Karnataka episode with Indian parliament episode just to support the evil cause. In Karnataka BJP is a clear winner and only short of 2 seats to form the govt. Whereas Congress did not have 1/2 of what is required to form the government in center. They had to woo as many small parties as possible to form government and when big fish (Communists) withdraws support they have to survive on several small fishes. There is no secret that its their duty to to appease all as nothing in this political world comes for free. To the worst, our PM had to join hands with all sorts of goons like Mulayam, Amar Singh, Lalu etc. to come out of the danger.
Coming to performance of this government, people have aptly replied in several assembly elections.
NDA was tough on terrorism because they caught the culprits at least (Now UPA protecting all of them in Jails in the name of secularism). The Afghan flight episode was bad, but India was not ready to sacrifice its travelers and the Congress supported the decision to bring the innocent travelers back. Advani did not like the idea of exchanging terrorists for innocent travelers.
The prime thing is whether N-deal good or bad for the country. It was initiated by NDA, but apparently the safeguards were changed by US soon after UPA took over. This is the sole reason BJP rejected N-deal in present format. Please read more articles on this issue for bettering your assessment.
