Why do engineers opt for MS?
A degree in civil engineering is quite a mixed bag of general understanding, principles of practice hence forms a shallow basis for a curios mind especially when one is majoring in a specific area of specialization.
MS offers an opportunity for most engineers to specialize in given field and additionally to be competently set for work opportunities such as tutoring in colleges or universities or even continue with research works and publications.
It's masters degree. If you do masters from top universities you will get higher package jobs. If you are really interested in any topic and you want to learn more about that topic masters helps you. Some companies provide you scholarship for your MS if you want to do MS.
If you do your master's you can work in any engineering colleges and it would be better than working in IT or MNC companies. If engineering students won't get job they opt MS and try to work in engineering colleges.