B4: The Lost City is a classic module for D&D. At one point it (in)famously stops giving full description of the rooms but instead lists monsters in each area and tells the DM to figure out why they're here themselves. Once the reprint will show up in new anthology, I'm sure people who complain online whenever WotC uses "ruling not rules" or "DM decides" or "these parts were left for the DM to fill in" in their design (and then continues buying WotC books to keep bitching and doesn't touch 3rd party or other games for some reason) is going to be normal about it. /s
To go one step further, it's not just that their customers will fill in the gaps, they'll also take the blame.
The DM struggles with a products that provides them with little to no support? "Skill issue. You just need a good DM."
The DM works doggedly to fill in and paper over the gaps? Sure, they'll appreciate the DM, but WotC gets some credit because "This module is so much fun!"