It never is. Unfortunately POET was not the exception that management thought it was in terms of the amount of work required to commercialize this technology. It is a very major departure to how integration is achieved today which represents a big barrier to entry for other companies who have tried to achieve monolithic integration. 

If it can be fully achieved then it will not represent a sliver or even a slice but the whole pie.

Now let’s see how much of the pie they can get with DL and BB.