They cannot make their own trainsets, cars, and consumer goods to fulfill local demand aside from food. India is on the road to privatizing many of its industries, but if you look that the list of GoI enterprises versus public private partnerships and the endemic levels of corruption (or else ethno-fascism) it is likely these are going to succeed anything soon. Indias largest exports are ideas and philosophies like religion, and I bet in the future it will be manufacturing and operating philosophy like Japan did with Kaizen.
India is a good place to go to offshore costs for space, and many countries do. They know how to squeeze the inefficiencies out of a process (and also not pay people, but that's another story) and bring down the costs of a mission. But there is nothing novel about the missions themselves. There is nothing pioneering, and there is nothing wrong with that. This is the case with Japan. Most of Japanese innovation is actually from US companies that they took over.
In any case, it's important to be realistic-- it's nothing to do with India being poor. They are not poor. They can afford a lot, and do a lot. Some people are in the mindset to accomplish a great deal mentally. Most people are not and still throw banana peels into the highway after eating them. No country without a basic civic sense can (in the immediate few years) have the R&D capabilities you speak of in a meaningful fashion.
Maybe in a few decades when people are more educated.