The reasons are multiple, the basic premise was ok, but often the lame phrases you learned were totally useless in most situations. There was little in the way of actually teaching your the rules, endings and restructure, no real cultural content and the photos are the same from language to language. It is a cookie cutter system at best. I did it, twice, and got nothing out of it. I could go on and on....
Recent reviews of Rosetta Stone also reflect this. They sunk a lot into advertising and less into content. Almost never any updates either or additions to your course as if all you need is what they give you . Innovative Language lessons on the other hand are updated every week with new lessons, documents audio, video, writing assignments etc. All done by Native speakers along with one who is not. Miles above Rosetta Stone.