

I think they just had to put something there, so they threw in a joke. They probably never expected it to be visible or readable.
It’s similar in nature to how the DS9 promenade directory has “Yoyodyne Propulsion Systems” from Buckaroo Bonzai, albeit a more dark-humored example.
In universe, it doesn’t exist, I’d say. It’s just a part of the aesthetic, similar to how some things on TOS would look less hokey in real life.
How do we know the whole Star Trek franchise isn’t some Romulan plot to erase the Federation from the timeline via butterfly effect?