Because landmines have been historically used in more places than on land? Reactive armor comes to mind as a good example, as well as anti-personel mines used in urban environments i.e. the ones that have a tripwire across a doorway. Also yes, they do make landmines that are directional, which the damage done to land in the game is a good indication that these are directional landmines.

Btw, making this not as an argument against the mod, ik people have their playstyles. Just wanted to answer the question proposed.