Go on. Your idea is to make the process more complicated or timeconsuming. I don't see how exactly more complicated helps here. Are we talking "new-players-won't-understand-it-and-die-of-thirst"-complicated? Obviously TFP can't go that far. But then what?
I don't want to put words in anyone's mouth, but to me it isn't water that is scarce. It is the knowledge and resources needed to purify water that is rare. Most people think boiling water is enough to purify water. It's an important part, but not a complete answer. But that's reality and the game is more important, which comes down to what the goals are for the game's experience. Like many (most?), I'm happy to wait and try A21 in the spirit of the evolution of the game, experimentation, etc. I may even like it. I'm trying to keep an open mind despite my criticism. I suspect TFP and I have the same goal -- a more lengthy period of time where water is relevant to game play.
What I see right now, based entirely on what has been presented, is that fresh water scarcity is desired and that the scarcity goes away around day 3-5 depending on when you can get a water filter and make a dew collector and that murky water is a common drop that can be converted to boiled water once you have a cooking pot, also probably meaning potable water is not an issue after day 3-5. Somebody who runs everywhere might need two Dew Collectors or at least dedicate one spot in inventory to carrying around a cooking pot so they can boil what they harvest from POIs when they need it. (I usually carry a pot and a grill, but then I'm prone to play as a nomad, so "home base" is my vehicle's inventory.)
After day 3-5, players with goals that require a larger volume of water still have to work to improve their capacity to generate water, which will be in the form of more and more dew collectors.
Carrying water away from a lake works around TFP's ability to control the pace at which murky water is found. They can otherwise control the loot lists and tune murky water so that it is more or less common.
So, to me, I wonder if this new arrangement actually achieves the goal. If the goal is water scarcity for 3-5 days, then it sounds like it does. I look at 3-5 days and think it could be longer. To make it last longer, I think the best course of action is to make it so that boiled water still has a chance of dysentery. This leaves the more advanced water (made with coal and a plant) to represent potable water. Dew Collectors and Boiled Water becomes an important step, but not a complete answer.
Thus, back to the opinion I expressed above in this post, the limiting factor blocking unlimited potable water isn't really the availability of murky water, but the knowledge and tools to make potable water, which I think can involve more in-game effort to establish and lead to a scarcity period longer than 3-5 days. It wouldn't really matter if you can carry water away from a swimming pool, unless murky water were good enough for most recipes.
Which is the better game in the eyes of the masses? I have no idea.