Haven't read much of the blog yet but I've dealt with this in more than just music. It's fairly natural, humans tend to be highly motivated by new things to discover and loathe things they become tired of - it's all about the discovery. Once something becomes old hat, it has to remain as such until it (or more importantly aspects of it) are reintroduced at a later time and mixed in with something new to create something that is a new mystery all over again - instead of being "retro".
You'll see it everywhere you look if you are aware of it, whether that be clothing or music or car designs, it's often new combinations of older things. I'm doing that right now in a recording project where we have plenty of stuff that could be (is) dated and we try to apply something to it that is fresh and/or unexpected - like "let's make this bowie sounding progression more bluegrassy" as a made up example.
Another theory... Well I forgot what the hell that was, will reply when I remember.