I've never really understood why the US and India don't have better relations.
It's really simple. "better" relations with US means India would have to be US proxy against China. Indians don't want that.
Pretty certain India isn't big on China. Any relationship with them is one born more out of self-survival.
“It may be dangerous to be America's enemy, but to be America's friend is fatal.”
― Henry Kissinger
For fuller context.
Kissenger according to Buckley said:
Nixon should be told that it is probably an objective of Clifford to depose Thieu before Nixon is inaugurated. Word should be gotten to Nixon that if Thieu meets the same fate as Diem, the word will go out to the nations of the world that it may be dangerous to be America's enemy, but to be America's friend is fatal.
link
Yes, America has foreign policy issues. Much like how Russia/USSR has lots of blood on its hands too. The big boys in the sandbox all have lots of blood on their hands.
None of this means the US shouldn't have had better ties with India. We don't. Granted, the self-interest is likely the reason for this, and that sucks.