Why docker?

Why not? Docker (and the general ecosystem that has been built around it the last fear years) is a great way to run stateless applications.

Container are a lot less secure because you need to run as root.

You don't run the docker container as root (unless you're running privileged containers but that's not the case here). The user inside the container may be root but that is a different issue (and bad practice)

With less secureity comes greater ability to get hacked.

Why are you exposing your ELK stack to the outside world? Someone would have to breach your network, get an RCE on ElasticSearch, Logstash, or Kibana (not unheard of to be fair), then break out of the container onto the container host. Note the first step, get into your network.

you are almost directly handing your credentials over to underground red hat hackers.

Those pesky hackers.

To me containers have no business in the current state of linux servers.

Why?

They provide no security benefits

Docker/containers are not a security mechanism, they never have been. The recent moves towards containerization are bout process isolation not security.

and are too new to work prroperly under load.

You have literally no idea what you are talking about.

Now just to be clear, I'm not a Docker fanboy. Docker isn't perfect, containers in general are not perfect but they do what they advertise very well (process isolation). They are not "lightweight" VMs, they are not meant to be used in lieu of standard security processes, and they certainly have issues but spreading badly typed FUD does no one any favours.