Thank you for your response.
We use self-hosted windows agents and install OpenJDK on them. Typically, the JDK comes with JAVA_HOME environment variable and you don’t have to do anything else. It just works.
With additional “java” demand one would have to create this capability or environment variable manually. It seems to be a non-standard variable. Obviously, it is not a pain to automate an agent provisioning and incorporate the variable there, but it means additional effort and investigation on “why the task fails, when java is installed on my system”. Then you just realize that there is just a specific demand added by a task and you need to address it.
Ideally, if something requires java (or anything else), it should work out of the box when java is installed with default values.
Currently, the extension does not explain its pre-requisites and it is not that obvious, that it will add “java” to demands for classic pipelines.