In big companies ops trumps devs, and it's correct because they develop for 6-12 months and then operate that sw for 6 or 12 years. Been there, saw that (a mobile phone operator). So if ops says that docker is no-no for deployment, the dev has to work with another technology or convince them that everybody is going to benefit from it.
Startups begin as small companies and small companies have a single team that decide how to develop and deploy. Usually developers deploy and take care of production too. What's convenient for development often trumps what's convenient for production, at least for the first months or years.
You're presuming that the same company develops and deploys the software. My company runs many third-party Docker container-images in production—precisely because a Docker container-image is the only format that software comes in.
I've seen ops accepting to run a couple of services on Windows and Linux at a time they were all HP-UX and Solaris.
There were no good alternatives for those services so ops were not happy but had to learn how to operate those servers. Can I suppose you went through the same?
I (single dev at my startup at that time) adopted Docker 0.4 alpha and i have grown with the docker ecosystem. Today we pay for codeship,etc.
there is zero chance i would have a Docker buy-in if I could not get started then. This is the case with Docker Swarm and k8s today.
I'm struggling with k8s... while the evolution of Docker -> Docker Compose -> Docker Swarm is fairly easy and incremental.
In 2 years time when I have a large devops team... i will spend money on Swarm. Docker Swarm is conquering from the bottom. K8s still has a chance... but it is choosing to compete with OpenStack rather than Docker Compose, which is a big mistake IMHO.
Startups begin as small companies and small companies have a single team that decide how to develop and deploy. Usually developers deploy and take care of production too. What's convenient for development often trumps what's convenient for production, at least for the first months or years.