If you are just storing unused drives, I see no problems. If the drive is being used when in the cupboard, then the cupboard needs to be open and/or ventilated to prevent heat build-up. Most drives are NOT hermetically sealed - that is, they are not air tight, but they do have a moisture barrier so I agree that condensation should not be a problem - again, IF the cupboard is open or has ventilation.
I don't see the need for one of those cases - except for when traveling.