In top colleges/universities there is more professionalism in the US, Otherwise PhD life deteriorates from top rated to bottom rated in terms of value addition. Nobody goes to bottom colleges expecting a job from that in the US. They are mostly for amateurs or people who are doing not for a job but out of self interest.
US PhDs are prepared for teaching jobs during their research with independent responsibility and US undergrads are prepared for research in their UGs, in top colleges better than their counterparts in India. Also US PhDs have to face oral exams without coaching by their profs. This makes them better trained and more confident in their jobs later.
Srn Ramanujam, Asst Professor, at Indian Institute of Technology, Kharagpur (1988-present)
Source: Quora Digest