The issue with Nitain is that there's nothing you can do to influence how quickly you get it.
In other words, you can't grind it, that is the point!
Also, there are a ton of casual players that log in three times a week for 1-2 hrs, and there's a chance they'll get 0 nitain.
Which one is better for a casual player? Being able to get something as a reward from a short mission, or spending your limited 1-2 hours with farming in Land of the Pressing 4?
Nitain is just a pain.
How is something that don't require an effort other than doing a 5-10 minute alert cause you pain?
You can just buy with plat the rewards from other players at a fair market price.
You can also buy items that require Nitain.
It's not necessarily the same people asking for reduced grind to farm Nitain.
With the current system, you need to be ready at all hours for a Nitain to pop up.
If Nitains were droppable, it would actually reduce the grind. Efficient grinding > time locked resources.
There is a large number of players who want less grind. There is also a large number of players who want to be able to farm Nitain. So there is a high chance for there to be an intersection.
If you feel like you need to be 'ready' for a video game progression, that is about you. You don't need to be ready for anything, you can just casually play and be like "Oh lookie, a Nitain alert" then spend a small 5-10 minutes on it.
If Nitains were droppable, THAT would be a grind. You can't reduce grind of something that is not grindable...
If I wanted 5 Nitain, as fast as possible, I would have to wait probably ~30 hours, assuming I get all of them.
And you spend that 30 hours in a dark room with nothing to do I guess, if that is such a huge problem to not be able to grind a resource in a 60 minute playdate with Apocalypse's Press 4 Horsemen.
It's like when you know you have a package coming by mail some time during the day, and you're afraid to go shower or do something else or you might miss it.
A package is probably something you payed for and something you really need. This is a free 2 play game with no one forcing you to play. If you feel like it is a duty to finish whole game in 2 days, you are not a casual player, and that is the point, Nitain is casual farming, not a hardcore grindfest that turns your 4 button grey like your future.