One of my rabbeim, who was a student of R' Elya Svei explained this to me as follows:
The yeshiva curriculum includes masechtos from nashim and nezikin, such as Yevamos, Kesuvos, Gittin, Kiddushin, Bava Kama, Bava Metzia, Bava Basra etc. for two main reasons:
- There are classic commentaries on Talmud Bavli, and these masechtos include more of the commentaries that are beneficial in developing a learning methodology than all the other masechtos.
- These masechtos include many sugyos that are central to the rest of shas and involve a lot of cross referencing and ideas that come up in many other masechtos.
Since the studies in yeshivos are intended to influence the way a person learns for the remainder of his life, these considerations are important in choosing the yeshiva curriculum.