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
I disagree - it’s not cowardice to want a complete adventure as a base. The whole point of buying an adventure is that it gives you a complete story from the start instead of having to make up your own. Coming up with reasons that monsters are somewhere might be a fun little writing exercise for some, but it should just be a blog post, not a product people are paying money to run their groups through.
It might be cowardice to not change or expand on the adventure as written to customise it to your group, but even then it’s a group thing - 5e in particular has lots of groups who approach the game with the same attitude they would skyrim or diablo, and their character is just a means for them to interact with the world. Changing the story for those groups doesn’t actually add anything to their experience.
I broadly agree about ignorance being a problem, but I still don’t think it’s cowardice to not want to do things you haven’t been taught how to, and particularly not with 5e - you don’t learn how to run 5e by playing 5e, you learn by playing other systems then coming to 5e because that’s what you can get players for. You play something like 2e and OSR or 3.5/PF1 and run 5e with the mechanics from those games in mind. There isn’t a mechanical base that rulings can be built off in 5e, so it’s not cowardly for new DMs to not want to have to come up with mechanics from scratch.
This is a room. After seeing dozens of rooms with monsters and furniture, you are given a room with nothing in it and told to fill it yourself. You know the general sort of thing that goes in the room, so all that’s left is to decide precisely what. Everything before the room has been given to you, and everything after will be given as well. You just need to come up with one room.
You can have a paid product full of things to put into that room and not learn a damn thing about actually preparing rooms like that. You can memorise every entry on a multiplication table and still not know how to actually multiply two numbers. The most valuable teacher is experience, which is why you have to actually figure out what the gaps in the number sequence are.
So you can try. You can come up with a few monsters you think would be fun, and would fit into that room. You add a bookshelf and a table for flavour, and to make the fight a little bit more interesting. It could go well or it could go wrong, but you learn either way.
Or you can rage against the system that dared tell you to figure out a single room by yourself; dared to tell you to put your pride on the line and risk making a mistake.
The second one sounds cowardly to me.