Yeah...it's like, when I was a kid, I always wondered why we weren't allied with/pretty friendly with India. It's the world's largest democracy, not much more left-wing than plenty of European states, is in a strategic location, etc. It seemed to appeal, much more than propping up Pakistani or Iranian dictators did (or had; I wasn't alive when that was going on). Missed opportunity, it was. But then I have had a slight Wilsonian/idealist streak for a long time...
India was the issue there. India's leaders, start with Nehru, leaned towards Marxism but wanted free enterprise as well, which is how the License Raj came to be. They were not friendly with the West at the time, and the ideas of Soviet-style planned economies and equal rights for all dovetailed nicely with much of the ideas promoted by the Indian government, owing in large part to their bad experiences as a colony of Britain. I don't think it was so much a missed opportunity as Pakistan being easier to deal with.