Quality translation is not cheap. This is partially because there are numerous places where the market for it is not as efficient as it could be. However, it is mostly because it is freaking hard. (I do J->E technical translation for the day job on occasion. You need to have a superset of the knowledge base of an intermediate Java engineer to do it well. I got to rewrite a description of what a SQL injection attack was written by someone who had never used SQL, who faithfully translated a description they found in a well-known Japanese desk reference for engineers. They produced comprehensible English which was, well, wrong.)

Come to think of it, translation is a classic market for lemons, isn't it. The people who need it the most are the least capable of assessing the quality of the deliverables, which is why everyone here has heard of All Your Base Are Belong To Us. This results in both people paying absurd amounts of money for mediocre translation and, hmm, large companies thinking that their crowdsourced translation presents their company in the best possible light.

There's so many ways a crowdsourcing solution like this can go wrong. I wish I could show you a concrete example but I don't have any good examples of Japanese businesses that used the technique off the top of my head. If you guys want I can dredge up an example or two from Facebook or whatever, but I'm not quite as plugged into the Japanese Internet so I miss most of the inevitable snickering.