Many people have an interest in older tech because it IS and will ALWAYS be relevant.
Sure, modern DSLR's are amazing and simple to use, and instantaneous. But what does using it teach you compared to being knowledgeable about the technology that made it possible and desirable in the first place ?
Schools that teach people how to DO and THINK are ahead of schools that only teach abstracts. And integrative, functional knowledge is always vastly superior to a purely abstract knowledge that has very little bearing in the real world.
Many people interested in vinyl are also interested in the motors, the analogue electronics, the physicality of actually being able to fully comprehend why and how the devices work, how to actually repair and maintain them, and where these devices fit historically.
Contrast this to someone who has no idea how anything works, and just disposes of their shiny new toys, and buys another after a year of using a tech which they only have a very rudimentary knowledge of.
Also, the physical art of making a print from film you shot yourself is a process that point, shoot, edit and print is very different from, yet similar enough that a student can learn a remarkable amount about history, technology, art, mathematics, and physics from.
A more integrated and functional education.