iPhone 5 battery case

It has been 4.5 months since the iPhone 5 came out and there are still basically no battery cases out. Mophie and Lenmar's websites have said coming soon for months with no details on a release. I read a rumor that Mophie's isn't coming out for another couple of months. I'm genuinely curious about what could be taking so long. Is it due to difficulties of working with the new lightning adapter? I can't believe that is the case since Chinese knockoffs of the cables came out almost immediately. How hard can it be to make one of these cases? You get the dimensions of the phone, make a plastic case, stick a Lithium Ion battery in, etc... Even if it's true that accessory makers had zero details about the iPhone 5's dimensions or Lightning connector specs until day of launch (I doubt they truly had zero information) they have still had 4.5 months to build something. I'm pretty sure that I could have started a Kickstarter campaign back on 9/21 and have had something to market by now. Ok, end of rant.