In Star Trek, the first of JJ Abrams reboot of TOS in the movies, Scotty and his aide Keenser are both stuck eathing Star Fleet Protein nibs. (I think, Simon Pegg's brouge is pretty thick.) The science of food preservation is very good nowadays. Have SF Rations declined in quality in 300 years? Even Indian Army MRE's are very good. lordish
I get the idea that the outpost is both forgotten and/or largely ignored. Considering that it seems to be punishment for Scotty, I would imagine they get occasional shipments of the basics and nothing else.
Sometimes it's more of a "taste" or perception thing. Once people take a negative view of a particular food, they tend to keep that view no matter how good the food really is. Take "Spam," for example. Spam has a bad reputation, yet it's not a bad food (or else it wouldn't be sold all these years later). It's ham and pork shoulder. However, Spam or that type of canned meat was a common staple in WWII GI food packs. After eating that for years during the war, the GIs that returned home shunned it in favor of other foods. The reputation grew despite the quality of the product.
If you can't pop down to the shops and pick up what you like for dinner it doesn't matter how great the ration packs are.