Hello, level designer on the Listening Post gameplay segment here. The main motivation for me is to work on a free time project in modern middleware like UE4, which I use in my day job. This allows me to perhaps flex and learn in areas that my day job perhaps won't allow for due to time/scope/seniority/project/etc. It's good practice. It also gives a good opportunity for others to join and learn too, so that they may be better prepared for say - full time work in games. Like the way it used to be
I wouldn't say that building a known framework to allow this is stupid. It gives a good base with some known mechanics for people to work to and given the age of the source material, ideally improve upon.