I wonder why that is. It appears to work well for many projects.
Actually, no. It doesn't. At least not for quest mods. It works however great for landscape mods.
First lets get this out of the way:
Doesn't Kragenir's Death Quest do it like this?
KDQ is not episodic. It was released with ~50 quests, and is still around ~50 quests.
That's hardly episodic.
I've released a quest mod in episodes. Started with 12 quests, working upwards to > 60 quests with about ten quests in each update, then called it finished while secretly sneaking in more updates. However why did I call it finished then?
Usually after each release 90% of all comments consisted of just telling me why they won't play the mod. The majority essentially said "I won't play it until it's finished", that's said to a mod already available with a lot more quest content than, say, Shivering Isles. Luckily this has changed since I've called it "finished".
Imagine spending hundreds of hours into something, like e.g. a whole guild to play with a finished storyline, and then it won't find any player. Imagine being told while you churn out episode after episode that no one is going to play your mod, because it's not "finished". Even if there are currently not even any loose threads open. Even if the pure playing time already available surpasses Shivering Isles. You end up with like three players.
Great.It may have been different back then in the days of Gates to Aasgard and similar, but today if you do episodic quest mods, you're pretty much guaranteed to have nearly no players. All positive side effects you hope to get through episodic releases pretty much vaporize through this. Instead even the opposite can happen, that you get the strong feeling no one
will play your mod.
Was my mod an exception? I don't think so. I've seen the same happening to plenty of episodic quest mods, most modders however gave up instead of finishing what they started.
My advice: Even if you do episodic development for a quest mod,
don't tell anyone! People will love you if you expand your mod. Though if they expect it to be expanded in the future, they won't play it. Simply, sad maybe, but a workaround.