GCD timer is to high for melee and ranged physical dps.

Erm... Certain jobs can reach it already and in other games etc like wow there is a 1sec GCD on all skills anyway

Mnk video
https://youtu.be/ODWJkVXfUrQ

There is also a blm and whm i seen do it aswell but i cannot find the videos

I find it rather fast at 50+ actually, considering I can't just mash the same 2-3 buttons like I did in WoW to get good DPS. Preliminary mousetracking results show that I don't stay in any one place for extended periods of time, though the rotational area has a much higher density than the rest of the hotbars.

I dunno, I'd rather keep it as it is.

Longer GCD allows for more off GCD abilities and more complex rotation and fight mechanics. Maintaining some of the level 60 rotations, particularly in fights where your moving a lot, can be quite challenging. Infact one of the reasons WoW gutted the rotations of so many of it's classes in their last expansion was at least in part due to the devs wanting simpler rotations so they could have more mechanically complex fights.