I have to agree with rounser at least to this extent: published adventures, run as-written, are almost inevitably "railroads" and moreso than most console and almost all PC RPGs in that they offer very little in the way of sidequests.
Now, in actual play, does that hold up? Not necessarily. A really excellent GM can roll with player decisions and produce a compelling story and encounters. I suppose he could do so from the basis of a published adventure, though how or why I couldn't say.
Most average and even good GMs can't. Unless they purely improvise or have a vast amount of prepared material, they have no choice but to use "soft railroading" (giving players the illusion of choice - if plot hook a. is ignored, proceed to plot hook b.: if the players go south, the dungeon is south, if north, north).
Within the course of an adventure (a "quest" in PC RPG terms), players have more choice - though often less than is posited here -, but in choosing what they do? Far less.
Ask yourself not, "did I have the choice to switch sides, or leave the village to its fate, or ignore the fate of the world" more, "could the campaign have proceeded without a total rewiring if I had done so?"
If the common ENWorlder experience (as opposed to the very best experiences from a long and mixed gaming career) is that, yes, you could and no, the GM wouldn't miss a beat or need to prepare more material... well, you are, I suspect, rather more fortunate than the average player.
Now personally, I don't care. I prefer console RPGs to PC because they prize story and gameplay over options. They're "total railroads," which allows them to weave complex plots and characters and still deliver a dynamite gameplay experience. In P&P campaigns, as a player, I'd rather have a good storyline and make a character who fits it, rather than having all the options in the world... as long as they involve dungeon-crawling.