Is the OP asking
- why people prefer the side-by-side layout, or
- why people want lots of freezer space?
If it’s #1, you may want to look at this recent thread:
I think it was originally a poll (unless I’m remembering a different thread), but the poll part doesn’t seem to have survived the transfer to Discourse.
If it’s #2:
Some people like to be able to stock up on things that are already frozen (not just TV dinners and ice cream, but other stuff comes frozen too),
Some people like to be able to stock up on things that aren’t frozen to begin with but will keep a lot longer if you put them in the freezer, and
Some people like to make large quantities of food and freeze the leftovers.