Using Docker4Drupal in Production vs. its commercial Wodby solution
Disclosure: I'm a Docker4Drupal maintainer and Wodby co-founder.

We do not limit usage of our images, it's MIT licensed, so if you want - go ahead and deploy the images in production. However, you'll have to do some work before that, e.g. set up a router, certificates, cron, etc. Configuring usual stuff with containers is not always obvious especially if you're not proficient with containers. Since we already handle all of this in our platform we've added this recommendation (people asked us about production). Also, stability requirements are higher for production (including freezing the docker version).

Originally, we created docker4drupal just to provide a local environment for our customers (instead of connecting Vagrant) but later it became obvious that it is valuable for many drupalers including those who do not use Wodby. In other words, historically, it was prod > local transition, not the other way around.