I think Druids are better at getting AoE threat than Warriors because of all the prep work they can do at the start of a pull, especially if you need to tank 3+ enemies. For starters you can put your HoTs on yourself (bonus healing on yourself that equals extra aggro), charge up a kamehameha Star Fire on the skull, then let out some Moonfire frenzy on skull and the secondary and tertiary targets while strafing to get a little distance. I find this more fun and engaging compared to Warriors. Warriors tend to need people to be patient and wait for aggro and things can suck if RNG doesn't smile on you; stuff like missed attacks, resisted taunts, and being rage starved. Druids have more of an insurance policy.
But yeah... Druids lack in survivability. The fact they get crit and crushed so often really makes the bonus armor and HP not seem as mighty. Itemization is wonky for feral tanking too, and it's hard to get upgrades when advancing into T2 content and beyond aside from random miscellaneous items scattered here and there.
In the end feral tanks do offer some nice utility by serving as a tank/melee DPS, an emergency healer, and they got the neat toys Innervate and Rebirth.