I've repeatedly said that I think your opinion is wrong. And I think it's fair to say that you're exagerating a minor issue, or rather, an issue that all products face. ... I am not saying that it is unlimited, and by suggesting that you are being deliberatly obtuse.
How about you stop casting
detect thoughts and assume for a second I am posting in good faith.
When you originally used the term 'limited' you most certainly did not mean it as 'not unlimited'. You meant that there was only a small degree of fluff a writer could create, as indicated by your broader argument. This assertion is false.
Tis not.
You can write plenty of fluff for an adventure without running into the problem that you described, to the point where the problem you described is a minor issue at best, or more accuratly, the issue of adapting modules is ever-present and no more problematic for 3pp creators than other creators.
I know that from the first glimpses of 4e, I realized it would be practically impossible to convert my existing campaign. The span from one 3e setting to another is, in many cases, far less than from 3e FR to 4e FR. Virtually very monster, spell, or character class has a close analog between all editions from OD&D through 3.5 and Pathfinder. When we get to 4e, the ground rules change substantially.
Let's use a quick example. Assume for a moment you want to include a magical elven city. One possible adventure scenario involves rescuing a half-orc from a jail cell. Now, the first thing that might occur to you is that in 4e, elves are nature types who uses bows, not arcane casters. Now, you could make your elves different, but the resulting NPCs would be a little off. So you make them eladrin. Now, looking at the jail, you notice you have a different problem. Jails for eladrin have to have sustantial pits and barriers to keep eladrin from teleporting out. Your half-orcs needs a new backstory, since half-orcs in 4e are not strictly half-breeds, or not assumed to be. Finally, the jailbreak has to be reconceived, replacing a series of barriers and locks, representing a freeform obstacle, with a proper skill challenge.
4e is a different game set in a different world than previous D&Ds.
So let's come back to the matter at hand. So you decide to create your Eladrin city. Now, FR is already home to a number of settlements, so you can either design an alternative or decide your creation largely replaces some existing city. Eberron is going to look a little different. Because the religions of Eberron (religious mystery) versus FR (gods everywhere) are rather different, you have to make the religious aspects of the city somewhat modular.
So you decide to forget the city and just focus on the jail. You write a brief summary of what kind of city this is, which means it's easy to drop into an existing setting or to handwave, and you focus on the adventure at hand. Since we have a half-orc in an Eladrin jail, we skim the maps of Eberron and FR and make sure that's vaguely plausible.
We write up some NPCs, keeping any clerics purposefully vague as to their activities, we draw a physical design for the jail and we write up the half-orc and the jailers. The result is not a module so much as a scene.
This is why I GMd for years, honed my skills at adventure writing, and learned a game system inside and out, to write a
scene? My 3pp product, originally envisioned as a city trek with a daring jailbreak, has been reduced to the equivalent of filler for Dungeon.
It certainly is POSSIBLE to do more than this, but is it enticing? Is it practical? Is it rewarding? Is it lucrative? Is it anything, in short, other than mostly frustrating?