Much like in the swiftly-contracting newspaper business, I happen to stand by the conviction that in science fiction writers, the "whys" of a scene or character are generally more important than how those scenes or characters accomplish what they're meant to. There's always a place for description of important events so that the reader can be fully aware of what's going on, sure, but there is a threshold where a surfeit of description hampers instead of helps a narrative, as far as I'm concerned.
In science fiction this isn't too uncommon, though I think it has been moderating in the last couple of decades, with more and more tropes and gewgaws of the traditional "future world" entering mainstream reality. One impression I've got from reading back issues of Analog magazine from 1970 to 1972 is that back then, sf was far more of an insular niche genre than it is today, to the extent that no mean handful of stories seemed to have been written by and for engineers. Not that there's anything wrong with that, certainly, but it does present a significantly higher barrier to entry than what you come across in most fiction, or even the modern sf genre.
There's a passage in Mack Reynolds' 1975 novel The Towers of Utopia that put me on this path. While it's an interesting story - it'd have to be, considering that it was a Frederik Pohl Selection - I can't get past the impression that its two hundred and one pages are padded unnecessarily by superfluous description which, from a 2009 perspective, only helps to jolt me out of the narrative.
"Here he dialed a two-seater electro-steamer. ... He stuck his pocket phone cum credit card into the car's slot for payment and relaxed back into the cushions when it slipped into traffic. Since his destination was within the limits of Phoenecia, he remained in the automated, underground network of roads." (pp. 71-72)
Objectively, this is far from the worst offender of what I'm talking about; it's pretty light, actually, but at the same time it's what set me on this line of thinking to begin with. Beyond the somewhat didactic language of some sf of the period, my problem is that Reynolds described things that did not need to be described. As a reader, I don't find the mechanism of how Bat Hardin paid for his electro-steamer ride (electro-steamer? I thought this story was set in 2000, not steampunk 1900) to be particularly relevant to the story. In fact, when I read it for the first time on the streetcar last night, my first reaction was slight bemusement that Reynolds hadn't seen wireless device interfaces coming.
The problem is that these reactions will probably become more and more profound on the part of readers as technology diverges from the technologies incorporated into these settings. The concept of on-demand driverless vehicles isn't itself hard to believe; if technology keeps developing and the envirocalypse holds off, I expect to see them at some point before I reach the age at which I would've retired if the economy wasn't in such a damn shambles. It's just the nuts and bolts.
If the description had read, instead, that he'd summoned his car and whisked through underground highways, or something of that nature, I wouldn't have tripped up on it at all.