A Rhodes Scholar from MIT (a few years ago) is a sorority member. Often the Greek houses have a higher GPA than the campus average. It is not party party party.
Some (not all) engineers were not very social in high school and look for more social life in college. An organization can be an easy way to start to build social and leadership skills. In my sorority (at a big flagship, not a tech school) we had a fairly high number of engineers. At the time the engineering school was only 10% women and some of them wanted a social group that had nothing to do with the guys they were competing with in the classroom. They were looking for a social outlet that joining another engineering society, another gaming group, another ‘build a moon rover’ competition wouldn’t have given them. And we could build pretty good floats!
Greek life is very popular at a lot of engineering schools. I think they like the structure to their social lives. We partied a lot with Colorado School of Mines, and they all really liked structure to their lives. Friday after 5, all day Sat., at the library again by noon on Sunday. No parties during the week.