Serious question; I completely fail to see why there would all of a sudden be a gold rush here.
* There hasn't been some shiny new technology introduced (open source machine learning, maybe? Messengers with APIs have existed for a long time)
* There isn't some massive consumer shift happening that's new (messaging has been around forever. It's been crazy popular outside the US for a long long time.)
* There isn't some crazy new business model everyone's chasing
* There hasn't been some crazy UX breakthrough that solves text interface problems (high learning curve, ambiguity about what the service can do)
I can, however, understand why Facebook and Google want people to build bots on their new platform, hence the submarine reference.
Any ideas?