Despite how closely we run the risk of this turning into a "HURR WE R BETTER THAN THEM AT THIS" thread, welp...
CYD was really the best at what it did for those few golden years. We split off because (and apologies to Mitch where due) it was turning into...well, let's just say it died a very long, slow, embarrassing death. And WYS appears to have started even lower down the ladder of embarrassment at its very inception, with signs pointing nowhere but down.
Geeze, even the name smacks of the sort of 'taking the Internet too seriously' that we strive to avoid here. Nobody who frequents and champions a fetish website that happily allows pedophiles and zoophiles to post their wank material has even the slightest bit of authority to tell anyone else to 'watch their step'. Hell, the only things protecting FA from the same fate that IK brought upon e621 are the ability to hide 'adult' work behind a login wall and a few legal loopholes. Well, and the ludicrous amount of cash that furries seem to throw at the site which could potentially be used for a legal battle. But I digress.
It's all pretty hilarious and full of unwarranted self importance, but that's par for the course when furries are involved so no surprise there.