Kids who are just learning how to learn need to be allowed to let their mind roam free in order that they figure out how to learn.
If you would teach kids Gemara that is more geared “aliva d’hilchisa” you would have one of two problems: 1) You would limit their creative thinking skills due to inhibitions they would have about saying a shtickel that produces a halacha contrary to what they do all the time, or 2) You would have tenth grade shnuks making up halachos and doing things wrong.
In order to preclude both of these problems, and because Nashim/Nezikin does happen to have a lot of lomdus in in as many posters have already pointed out, it is worthwhile to stay out of “aliva d’hilchisa” sugyas until ones learning skills are honed and one truly “knows how to learn.”
That being said, I do think that a guy who really does know how to learn and has been sitting in yeshiva for ten years is wasting his time sticking to the “yeshiva masechtos.”