[MENTION=177]Umbran[/MENTION] Terrific observation!
I certainly understand why folks like less wall of text, and I do think there can be places where this is really annoying. But I also have to admit, as a GM, I like reading a module and getting pulled into the material a bit in advance. So I'll happily buy something that has that sort of thing.
Ultimately what does need attention regardless of approach to me, is what the players see, feel and interact with. For example, what an NPCs name, profession and background is might be less Important than how they smell, act, behave and are doing. So often, situations are static when they are hardly ever that way.
Good topic. Can you elaborate on what you consider to be a "wall of text" and what alternatives there are to explaining the author's vision of the adventure to the reader? If, for example, every sentence is useful, does that mean it's a "wall of text," or does it require a certain amount of less useful "fluff" in there? I'm trying to get a feel for when something crosses over into the wall of text category.
There's sort of two extremes when it comes to how an adventure communicates the author's vision to the reader (GM). Show or Tell.
"Show" is more like what [MENTION=85555]Bedrockgames[/MENTION] is getting at, where the adventure writer tries to bring the reader/GM's mind into the adventure's themes and motifs, so that once the GM gets it, he or she describes scenes and NPCs from that framework. For example, a Ravenloft adventure would draw the reader's mind into the Gothic Horror point of view, trusting their words to evoke something in the GM, and then trusting the GM to convey that as he or she sees fit to the players.
Personally, I like that approach because it emphasizes the strength of the tabletop RPG: interaction between the gamers. My group will experience the adventure a little differently (or perhaps a lot differently!) from your group and that's OK, in fact it's to be desired because it shows we're tailoring the experience to our groups.
"Tell" is more like what [MENTION=1830]Waylander the Slayer[/MENTION] is getting at, where the adventure precisely describes what the PCs sense. Traditionally this was handled with boxed text. In many ways this is the opposite of "show" because it doesn't trust the writer's words to evoke something in the GM, nor does it trust the GM to convey the adventure's themes or motifs without exacting coaching. For example, an adventure would include a breakdown of the main NPC's daily schedules, a brief blurb describing their appearance, roleplaying notes, and something akin to boxed text describing their lair/home.
Personally, I like "tell" less than "show", but I especially like it for situations where precision is important in the adventure (e.g. mystery stories) and as a teaching tool for new DMs.
Obviously, most adventures are both showing and telling, but some lean very hard in one direction or the other. When it comes to "flow of text" and "not getting eye strain", I've noticed that how deftly a writer switches from showing and telling (coupled with the art & graphic design) can do a lot to keep me as a reader engaged.