Honestly, as much as I love them: Imzy in its current form was never going to catch on.

Other sites can get away with some bad choices like login-required because of momentum, but... The culture and userbase they were hoping to attract was more akin to tumblr, and Tumblrites were never going to leave it for Imzy.

Those used to reddit, meanwhile, saw a signup/login screen (or even a "request an invite" screen) and boredly clicked off. Some actively looking for reddit alternatives (like me) waited to get in, but not many.