yeah, brands are a really hard thing to kill.
First as they grow, fandoms grown, and start self perpetuating. they create content, that is largely separate from the Official source, but still promote the Brand. starwars, to cars, to sports teams, etc... Then, this fandom, spreads into the casual market. An spread the word of the fandom.
Now, when the Brand starts fucking up, and shitting the bed. The casual market does not follow the news close enough to even know about this. They will keep on pimping the Brand on name recognition alone. And, the fandom, again was self perpetuating, and often far more interested in the activities around the Brand, then the Brand itself. From cons, to cosplay, to tailgating, etc..
The people in the middle who only give a shit about the product itself, are the ones that see the Brand failing, and bail out. but Brands can live on for decades from that casual market.