I can only speak for myself here, but I actually deeply enjoy the fluff-to-rules ratio with a few exceptions.
I mean, the lack of drones is *killing* me as a GM, because drones can make excellent (and bodies for AIs, until we get CAST/TRACES back). And while I completely do not agree with the chosen echoes given in DT, I know that Tmancers are getting their own buff down the line, so I'll simply ignore that they exist until I get that and have my rootkit back. There's other bits noted, such as the lack of creation rules for vehicles, spells, weapons, etc, which were given in the 4E equivalent books, but we're not looking at a complete rules line. Vital stuff first, cool stuff people want but don't *need* second.
And that said, I think the fluff is really important. I'm a GM by trade, and Shadowrun is an insanely complex and narratively detailed world. With each edition, there's more and more to remember. The short stories may not help you with a specific rules application, or even with specific operations, but they help in evoking that feel of Shadowrun. A lot of us are veterans. We can shut our eyes and see SR in all its grim, chromed-out, spell-slinging glory. But not everyone has that. New players need the world evoked for them, and a description and a few tips are no replacement for a good piece of fiction. I got into Shadowrun through the fluff myself, back when SR 1/2/3 had a rich library of novels and shorts. SR5 is getting there, but the books are a little more niche, and the short fiction in core, chrome flesh, DT, and so on are good, general slice-of-life examples of the world as a whole, as well as ways of introducing new shadowtalkers to replace the old ones, and new enemies and places and capabilities in a way that we can all intuitively understand.
And then there's Wakshaani's point. Chrome flesh, for example, has *more* 'ware than its 4E equivalent did. Its hard to fault them for so much fluff when it still managed to hit all the high points. Were parts of it poorly implemented? Yeah. Redliner needs more explanation, modular cyberlimbs are a mess, customized drugs are a mess, and chemical gland RAW is literally useless. But that's editing, not a flaw of *construction.*
I enjoy the current way the books are built, and fully support the inclusion of fluff. Part of SR's draw is the detail of such a unique world, and the fluff is how that is furthered.