Of course we should be good bargainers. But a bargain implies compromise and give-and-take. Do the leftists seriously think that the Soviet Union supported India without extracting its pound of flesh?
It is the same with the United States. We have to look at our own national needs. And in this case the PM seems to have got a good bargain. But the Left and the BJP oppose him on purely political grounds.
Finally, the question of the US dictating to India is not clarified. India can diversify its procurement of nuclear reactors and equipment. There are other countries waiting to supply once the NSG clears the deal. Much of the fear of US dictation stems from our inherent anti-Americanism.