Well, first of all, it's from like the very last bit of content in vanilla. It's almost completely irrelevant, being so late in the game. You have to kill the last raid boss in all of vanilla to get it. Anything with such a requirment is barely worth discussing in terms of making a spec viable.
Secondly, that's not a tank weapon. It has no defensive stats besides stamina. The attack power would be nice for a cat spec, but the item is kind of wasted on a feral druid and you'll definitely never get it. Not even worth considering. There are very good tank weapons for druids, this isn't one of them.
Bear tanks are alright as long as people know what they are. When approached from a perspective of "is this as good at tanking as a warrior?" the answer is no (usually). However, feral druids bring incredible utility and versatility. A prot warrior can't just switch gear and do 80% of a rogue's DPS. A warrior brings literally no utility whatsoever, and no buffs besides shout, while a feral druid brings battle rez, Innervate and crit aura.
Bears should not expect to be main tanks, but they make amazing off-tanks. There should be room in every guild for a dedicated feral hybrid. They can be either 14/32/5 or 0/30/21 (or 0/31/20), with the first spec being a DPS/tank hybrid while the second is a tank/healer hybrid. A feral druid can - and should - perform two roles, otherwise there's no point bringing them along as they don't tank or DPS well enough to do nothing else. Don't be that idiot druid who will only DPS, this is the one class that can perform two roles fully with one spec.
http://www.wowprovider.com/?talent=1122 ... 320215105n is the recommended spec, able to be either a tank or DPS as the situation calls for it. Note that feral druids don't really compete significantly with rogues for gear (doesn't use weapons and rogue tier pieces; later raids have feral-specific gear). The spec can be adjusted a bit to make it a great PvP spec as well by cutting two points from Thick Hide and putting them in Feline Swiftness.
http://www.wowprovider.com/?talent=1122 ... 520300501e is technically a healing spec with the ability to go tank when required, and is actually a popular spec even among resto druids who never tank (due to the +20% intellect from HotW). It's more of a healer and reserve tank, but is perfectly capable of OTing, you just don't usually cut a healer to get an extra tank. Still, if you want to be a resto druid who can tank, this is a great spec.
Note that most of the bear tank gear isn't from raids, at least not until later tiers where actual feral gear starts to enter the itemization. For a long while, your tank gear comes from 5-man dungeons, world drop BoEs, quests and crafting. Later on, the feral leather is both tank and DPS gear. This is crucial as you don't need to dilute your DKP (or whatever your guild uses) across two gear sets.
There's a few fights throughout vanilla where a druid tank is favorable, so it's a good idea for any raid guild to keep one around. Aside from those particular fights, it's also a much better dedicated OT than a warrior is because a dedicated OT needs to be able to tank quite well, which a warrior would need to be prot for, but also needs to be able to do something else on fights where they're not required to tank anything, which a prot warrior can't as they do basically zero DPS. They should also bring utility, which a warrior doesn't.
There are very good reasons for a guild to have a druid as their primary OT. Many guilds either keep a few extra prot warriors as reserve tanks or make their DPS warriors OT when needed. Neither is optimal. Prot warriors are useless when there's nothing for them to tank, and DPS warriors don't tank very well. Instead you can have a druid tank with enormous armor and health who, when not tanking, is a full DPS (feral DPS is decent enough, on par with hunters). This druid performs all the tanking duties that don't pertain to actually MTing the boss, and MTs the handful of vanilla bosses where a druid is the better MT for mechanical reasons.
Unfortunately, people are simple-minded and have convinced themselves that "druids can't tank" because they can't conceive of tanks doing anything other than MTing the raid boss. Those people are idiots. However, there are also idiot druids who think they should play feral as a pure DPS spec. Both of these groups of idiots hurt the feral druid's reputation. When used correctly, it's a very good spec that can do something that basically no other vanilla spec can: adequately fill two different roles in one spec without either role lacking anything.