I dont think they are bad people cheating their customers. It is really no easy job to create such technology plus all the tools, documentation and samples.

The real problem is that UDK and Unity appeared and attracted a lot of customers. I understand why. I mean, when I create a scene in Unity, then it just works. I copy all content into a folder and when I switch back to Unity, it just imports it, ready, done. I can tune materials and postpro effects, animate camera, make a video and shots. Ready. All this took me days, sometimes even weeks when I used UDK as an example.

I also played with Gamecore / Beyond Virtual and it always was unfinished. Many features did not work as expected and documentation was too short or even missing. Tools were really good but it was hard to get into it. Angel script as a scripting solution was a bit exotic too.

So in the end I think, they did not make tons of money, they had problems to survive. I mean, even Torque died and resurrected, but for how long? Since Unity can handle each platform plus Flash, it is simply not possible to beat them. It would be possible to be cheaper, but there is a free Unity version available too. So actually you could win only when you concentrate on a single platform and when you offer a better technology for this particular platform. Maybe a DX11 PC engine could be interesting, as an example.

Some technologies still survive because of lazy programmers. Many users dont want to switch programming languages and thus they prefer C++ engines as an example. There are raging fanboy wars in their forums when someone mentions C# as an example. But this is not a real objective way to evaluate such technology and the success stories prove it.