Not only that, after those cooldown changes, unguarded mines (e.g. near GECKO) are now full of camper PKs. They are camping there for hours, with heavy weapons a combat armors, waiting till you dig out some ores, and then they kill you. Or they just kill you before you manage to dig out something, to make you stop going there.
It wasn't like that before, since you could only dig like 3 HQ iron ores at once, but now, when you can dig out like 20 HQ iron ores, it's very profitable to camp and kill players there.
Conclusion: Pretty stupid idea.