Why would it create toxic behavior? I mean right now this limit restrict those that might have more time at the hand but cant do more that week thanks to the limit. At the same time if you dont have much time to play in a certain week you will fall behind because the limit is not taken over to the next week. Without a limit even a more casual player can gear up in their own time without the feeling of falling behind, maybe when they have more time while having a vacation.
About the question for Player D:
Yes if someone cant restrict themselves and just farm this for 16 hours a day than they will also soon get out of content but how many people are in this game that are like that? I mean raiders are a small percentage of this game the rest is much more casual. Yes theoretically you also dont need the gear to play dungeons but even without raiding some people might just want to see a progression and every piece of better gear will also increase your output thus making dungeon runs faster. So I just cant see why we should restrict the rest of the player base just because some people that raid would run through content too fast. If raiders were the majority of the player base this might be bad but it seems that most people are casual.
Lets not forget that this lock out is not only there for the fighting jobs. You also have those restrictions on gatherers and crafters and if you want to gather/craft everything you need the gear (or have lots of gil to buy it). For example I want to get the achievement for the fisher, where I need to gather lots of fishes at least once. Yet I cant catch a lot of the higher HW fishes thanks to my low gear. So I wanted to upgrade it with red scriptures. Thanks to the restriction this took quite the time..it was not fun since I only could fish for a small time till I reached the limit..at the same time I knew that I can only upgrade my fisher and need the same time again for the other two. Without the limit I would log on much more and maybe even fish everyday while I still have the time to log in that much. Also having the gear sooner would not mean that I would log in less, because fishing those fishes still will take quite a lot of time but I could not do the content I wanted to do because I needed all those weeks to just gear up and its not like this was a grind or something.
I mean they could have a lock out for each patch but after a new one comes out they could just increase the cap or maybe take the restriction away. This way you would pace the people in the recent patch but other people can still catch up in the next one. At least take it away when the expansion is over. SE strangely makes everything easier over time and yet somehow those restrictions especially on gatherers and crafters are still up.
And for those that just get through content too fast they could still put another carrot behind it, maybe a mount or something that is more expensive.