I think op is mixing two different things: a) the boards, shown in op can be (are created) with kicad, and b) these boards are not meant to be used in kicad further.
If one wants to add these boards (for extraordinary reason, like this one: How to implement a breadboard in KiCad) rectangular pattern footprints (aka breadboard) can be easily created with footprint generation wizzard, or array tool. There is no reason to add these kind of footprints in kicad library, because there is no reallife use of yhese boards in kicad. Kicad is a tool to create these types of boards, not to prototype on them, like mentioned in a thread linked in this post of mine.