As a 40 MIN and 31 BTN I know how fast you can gather items. It would destroy the economy on mats if a player could go gather items all day. I am in full support of this fatigue.
However, I don't believe a failed gather should give half SP. There should always be the option for a DoL player to rank up their class at a reasonable rate and a system designed to harm RMT should not penalise players who want to do this.
Rank 45+ is already bad enough due to the lack of grade 6. I would love to see a dev comment about that. Some change needs to be made and I can see the problem of adding grade 6 now (lots of mats for 50+ gear with no current use). The easiest solution is to boost the SP obtained when you are on the current grade. SP is fine for hitting a grade you can't scan for, but it's a problem when you're on the optimal rank grade and getting close to the next grade, especially when you're in the high 40s and can't hit a higher grade.
I can answer that. It's not shared. I've tested it. It's easy to test because if you hit fatigue on say botany, go mine afterwards and see.