Why did the TOS films never bring back Carol Marcus?

[Laura Cynthia Chambers]

Replace the bridge, but not the Klingon food packs which apparently, for unknown reason, our heroes had eaten for three months even though they were on Vulcan and fully able to get regular food.

It may only have been Scott that ate them - if he was dedicatedly working day and night to fix the ship, he may not have always taken the time to go for regular meals with his fellow crewmates - grabbing whatever was handy instead.