As far as Hifi goes you have a point with the 80s stuff being much more flat response. I remember I've heard some very good speaker with a fairly flat response and a good tansient reproduction back then. The Elac EL 150/160 series come to my mind or the I.Q. Trend (if I remember the names correctly, it's more than 20 years ago). The Hifi dudes had a term for that linear response, they called such a speaker "analytical". The stuff with the pimped bottom- and top-end was called "emotional". Seems the market went in the "emotional" direction from there
Back then I actually had fun listening to a good stereo. But in the last 15 years I've not come across a stereo (other than absolute high-end-stuff)that reproduces music remotely true to what we hear when we record and mix it.
If you think about the fact how the Yamaha NS10 became became a studio monitor from originally being a hi-fi speaker, then it becomes clear that stereos were always meant to be FRFR, but they are just not (anymore).
Christoph is right in this aspect, but that's only theoretical, in the practice real FRFRs will always sound "truer" and therefore - to some of us - better, than hi-fis.