Because there are people running businesses on dotCloud currently?

Because, at least in my humble opinion, it's actually better than Heroku?

Because, at a minimum, cutting it off at the knees would engender tons and tons of bad will amongst their current customers?

Because the customers deserve a couple of 'writing on the wall' style posts like this to begin thinking about migrating to alternatives before the cutoff is actually announced, forcing their hand in what could be 'too short a time period' to get migrated?

The more time they buy their existing customers before dismantling what works, and what people are paying them for, the better.

That said, this is the 'writing on the wall' that people should be looking for alternatives, at the barest minimum.

It may not be the writing on the wall, since running a docker PaaS will be a useful way to understand ... what problems you encounter while running a docker PaaS.

But we'll see, I guess.

It would be irresponsible to their paying customers to just kill dotCloud. I have no idea how much money they are making from it, but whether they have 100, or 10,000 customers, they owe it to them to provide them the best experience possible whether they are ending dotCloud or keeping it as a going concern.

Frankly, docker could be (and probably is) a great marketing tool for them to basically say, "Docker is great, and if you are looking for a cloud hosting, check out dotCloud." Even if docker related services don't make a lot of money right away, dotCloud is something that is making them money today.

Dog-Fooding. As long as you have an in-house product that uses the infrastructure you build, you'll immediately notice when things go wrong.

Sometimes you have to build products that make enough intermediate revenue to get you to where you're trying to go.

PR. Witness how everybody goes apeshit whenever Google closes a niche service.