Problem : Some streamers recommend cancer rotations to their viewers / discord

It consists of grinding on 7/8 packs of mobs while only 2 packs are more than enough

Result? Everyone stupidly copies them and instead of having around 20 grind spots, you'll only have 3...

Solution: put a dekhia-style system, a totem at the center of each rotation, the further you move away from this totem, the more the loot / trashloot decreases

Of course there will be a totem with groups of 2 packs of mobs, others with 3 packs of mobs, others with 4 packs of mobs etc just to satisfy everyone

I know they can just add Marnie but I never liked this Marnie system in an open world game..

It is nice that there are some grindspots with this type of mechanic, but I personally enjoy moving from pack to pack of my own choosing and learning the overall terrain of the hunting ground for myself -- and would be regretful if too many grindspots used this sort of dehkia mechanic in which rotations were so clearly demarcated. 

I prefer not to research rotations before going to a grindzone, and meander until i find a pattern that is satisfying to myself; checking rotation maps later on to understand what people are doing. 

I think some of the best open world grinds were when Serendia Elvia was at its peak: players would do their chosen rotation, then get a weapon-buff causing them to clear faster and therefore expand and enter conflict with neighboring grinders. It was messy and organic and exactly the kind of thing that I believe makes open world grinding lively and interesting.

I like both tower spots and rotation spots.  While places like Gyphin Underground are nice, I also like going to grind spots with a race track as well.  If it was only tower spots it would get boring, and it is also boring when it's only race track spots.

Its only PVP when its you who full buff and PVP addons vs guy on grind spot on running buffs, but when its NW/RBF/AOS - nah its not PVP.

You missed the point.  Re-read the snippet I replied to.