> I don’t really get the nostalgia angle as it seems as many of those who are into this kind of thing are too young to have ever been in such a space, let alone worked in one.

I developed a fondness for 1970s interior decor/styling even though I was born in 1988 because most of the places in my town, such as the library, were last renovated during that time.

Also, many people in my life, such as uncles & aunts, were still living in the homes they purchased in the 1970s and some design choices just can't be easily/cheaply changed.

I grew up within and around a ghost of 1970s architecture and design. As an adult I wound up moving into a suburb built in 1968 for this reason.

It's less nostalgia and more like a vague sense of familiarity that you can only scratch the surface of in your mind.