I'm a firm believer that if you want something in game, you are willing to invest the time, you should be able to get it.
For most, i95 is a glamor, and possible an upgrade for an alt.
Yet the time to obtain the materials far outweighs these benefits for many.
Maths?
8 person group
Each wanting a weapon (1 may be new otherwise, 8)
Let's estimate 1/10 chance based on Mastercraft/Fieldcraft III
10 minute, no wipe run
You can desynth 3 types of weapons (gsm most likely)
So for every 10 minutes you grind, you have an incredibly low chance of getting the demimateria for your weapon. Near some state lottery numbers I think.

Help us Yoshida-senpai, you're our only hope!