The differences between the equipments of tikal and inferno or inferno and gorge was much bigger than the difference between gorge and new red gear.
So why should someone, who already have full gorge equipment, getting new red gear. You don't need that gear, because first: it is similar the same like gorge and second: the new instance is a joke in difficulty.
Not only the player who still run the new instance are complaining about the new system. If you would have thinking about and for the community, the 5 cores would have been at least unbound for trading. The allmighty core could still be bound, but as it is at the moment, the economy will be stagnated, player will be frustrated etc.
It's your choice as playernet yes, but it's also your problem in the future if there would be a future for this server