Are you sure your assessment is not just some sort of cylical 40 retrospective nostalgia?
Now, I will concede that in the 90s people did not see the 70s in this way (at least not in general) - not long enough had passed, I think. That's why I suspect that any notion of the 80s being a culturally rich decade comes from the fact that it is now 30-40 years ago, rather than just 10 as it was at the start of the 90s.
This sort of view doesn't have much to do with anyone's experience of the decade as it happened, and I think it doesn't have a lot to do with what actually happened, because in any given decade, there will always be a rich and diverse set of amazing cultural creativity. It comes mostly from time passing, and a new assessment blending with nostalgia for the culture that surrounded as we reach certain ages.
I think the hint is in the examples you're giving : the 1970s were the heyday of progressive and what is now called "classic" rock, and that particular genre seems to be your frame of reference.
Whereas for us Euro synth folks, the 70s was the age of early pioneers like Kraftwerk, Vangelis, Jean-Michel Jarre (I suppose that's where rock music was in the 50s)
And the 80s are THE golden age of synthpop explosion that put us on the map, with legends like : New Order, Yazoo, Depeche Mode, Soft Cell, Bronski Beats, Eurythmics, Jean-Michel Jarre, a-ha, Tears for Fears. Our 80s are rock music's 60s (think Beatles & Rolling Stones).
The 80s are so revered that for the past 5-10 years there's been a whole music genre ("Synthwave") dedicated to reproducing its aesthetics with a contemporary twist. It's even been preempted by mainstream pop recently with The Weeknd's "Blinding Lights" single.
Our own Led Zeppelins are 90s kids Daft Punk, Chemical Brothers, the Prodigy, Fatboy Slim.
In the 2000s, we took over for good and mostly killed any remnants of rock music's mindshare in Europe, and the US followed in the 2010s with the "EDM" mainstream pop flavor of our stuff.
In other words, it's all a matter of which bubble you're living in !
It's true that the 80's "gave us" synthpop, and although I'm aware of the new level of reverence for some of it, I don't detect the more critical younger minds regarding it with the same level of awe that is now accorded to what happened to rock in the 1970s. My sense is that people like the sound, find it sort of fun-nostalgic, and are recreating it. Nobody views any of the bands you mentioned (I have the first singles by all of them, by the way, on vinyl) as truly ground breaking.
I could be wrong.
Personally, I went from Euro-synth stuff into ECM, improvised music, indian classical, progressive house and downtempo :)