"Premature optimization is the root of all evil" -- Donald Knuth
Translating the old suggestions [1] to the realm of devops, I think the point really is: if you are fairly certain that your optimization (k8, docker and so on) will result in "better" code and practices right away, then you should do it. If not, you shouldn't.
I personally find this stuff to be way overkill in a lot of cases. Does Kubernetes really accelerate your development process? If you are a two-men startup, your objective is to find ways to deliver value as quickly as possible, not to play at being Facebook. When you become Facebook (or even just Basecamp), you will then have enough resources to do this optimization. But if you feel your development process is really so much better with K8 and friends (because it's what you used in a previous job or something), by all means go for it.