Why don't Indian universities pay adequate importance to the study of humanities and social sciences for engineering students as compared to the ones in America?

Because it emphasizes engineering for engineering students.

Note: I wrote this before the question was changed to only discuss Indian universities. Don't engineering students already have to take enough humanities classes?  For example, CS students at Carnegie Mellon (which perhaps we can consider to be engineering, since many CS students go on to become Software Engineers) have to take a writing course, a communication course, one humanities course from each of three categories, and about three additional humanities classes.  I will take about 32 classes at CMU, and 8 of those must be humanities, so that means already one quarter of my education is in humanities.

I think its because Indian Universities feel the need for the student to focus all his time and attention on engineering relevant subject material. They must feel that any time spent on other material like social sciences arts will only take away from the time needed to learn and study the engineering subject material. American schools typically require more a lot more diverse curriculum for their engineering students; their belief is that to get get a better scope on your studies, you need to broaden your horizon and thinking capabilities. In my opinion, it is better to be well-versed in a multitude of topics regardless of its holistic benefit to a subject in engineering.

Most university curriculum in India is concerned with employability of an engineering candidate after studies. In this context, humanities and social sciences, at a superficial level, do not seem to add any benefit to a student and hence are not given enough importance.

Please correct me if I'm wrong, but I feel this outlines the main reason: 1. India is a very competitive society, not in the least when it comes down to education. 2. Humanities and social sciences are generally seen as inferior to engineering subjects. 3. People who study humanities subjects are therefore (falsely and unfortunately) seen as people who failed to succeed in studying engineering subjects. This, I believe, goes for the corporate world as well as for the social surroundings of the individual. - An example: Many engineering students end up trying for IAS, a branch of work that perfectly suits Humanities students. However, since humanities is seen as an inferior subject, studied by students who are (again unfortunately) seen as inferior/less intelligent than engineering students. 4. Therefore, to come back to the first point, in a competitive society there is no time to "waste" on subjects that are seen to be inferior. On a positive note, I do feel that this is changing and Humanities subjects have seen a slight uplift over the past few years. It is not for nothing that IIT Madras quite recently opened up a humanities department, which by all means has caught the attention of many engineers.

Aside from it being required... the whole point is to broaden your horizons, so to speak. As an engineering student, I pull ideas from all sorta of places. The whole point is the make a good engineer. The best engineers aren't taught only engineering, because that doesn't help you in solving problems creatively. You are required to take humanities classes so that you are less likely to get any kind of tunnel vision and b-line straight to anything. To put it simply, it's there to hopefully put a little more "stop and think" mentality into what you are doing.

Not sure which particular education system you're talking about. In general, delivering a basic background in all necessary fields is the job of pre-undergraduate education. So, humanities and social sciences may not be emphasized that much per se. But various universities do allocate a couple of subjects for non-engineering subjects mostly related to pressing social issues, as part of their engineering curricula. PS: I had environmental sciences as a compulsory subject as part of my curriculum of Electronics and Telecommunication engineering at Mumbai University.

India has a very rich culture compared to America. As such, every Indian kid is brought up amidst a very heterogeneous crowd, and grows up with a variety of social experiences. As such, bookish knowledge about humanities and social sciences is not deemed necessary at this level of specialisation, since the absolutely necessary knowledge such as the civic/political structure and the national economy has been covered at school level. Instead, engineering institutes focus on imparting technical education, which may be due to the naivety of the educationalists in assuming that technical expertise is the only factor in creating employable engineers.