If they wanted to avoid piracy, I think it might have had some potential going the legal route as well. It would be a nice interface to browse legal movies, documentaries, web series, etc.
Strange decision, I could see a company like Netflix buying them out for a rather large sum of money, within a short period of time.
As far as using it as a stepping stone to future jobs, why wouldn't they run the application longer? They pulled the plug before it became a widespread success. It they waited longer, the name Popcorn Time would actually be recognizable, which would be great for their résumé, kind of like saying you developed Napster. Now, they'll mention they worked on Popcorn Time, and have to explain to everyone it was an app to stream torrents, that had a brief shelf life.
They really should have road this out longer. Even the name was catchy. Someone else is going to fork the project and achieve the success they would have earned.