Thats how default CoPlanar selection works:
Left: we pick any face
Right: run CoPlanar selection.
Those behavior are okay, cause allow you to select something fast, but sometimes (pretty often, actually) it creates problems, because some part of the model can contain coplanar faces which you dont need in selection. And sometimes you can overlook that selection was wrong.
Real case example:
Left: selection which i was needed
Right: selection what i actually get. All those extra faces are should not be in selection at all.
In 3ds max behavior of selection like this are opposite. You enable βcoplanarβ tool and pick some selection.
All faces marked with green are actually coplanar, but you can select them one by one. The selection will be automatically stop.
I guess max are look which face are coplanar to the one you clicked first, but then automatically terminate further selection if angle between already selected faces are >x or something like that, i dunno.
Maybe some one see some addons which makes coplanar behave the same way as in 3ds max with restrictions like that?