It has lots of inertia. The reduced controllabiity is a trade-off. Being "well designed with properly distributed weight" doesn't mean it isn't harder to control (it just makes it not worse than something "poorly designed with improperly distributed weight").

It's hard to imagine how a significantly lighter set-up isn't easier to use. It's odd to see people suggesting that isn't true.

If one is using a heavier setup, then, presumably the trade-off of being harder to use had better be worth it.