Yes it is perfectly fine to join the course, What do you mean by what happened that I can not understand ( in terms of what you are expecting) still some possibilities I tried to figure it out is.
- You will explored and faced the most nerd people of the world at same time same day through out 2 years
- You will ended up with good quality exam system and extra curriculum which you never experienced in your bachelor day.
- You may have a choice to look into future with different prospective
- You may get time to prepare for PSU or any foreign nation jobs ( if you are interested)
- If you like to explore your career in research its good platform to get into good foreign university through IIT.
- Well Machine design is good trade as well compare to thermo.
- Hostel and campus life of IIT is awesome if you are extraordinary and not mediocre