Maybe. But you do lose some transparency and repeatability - it becomes harder for others to understand and use your Dockerfile. They suddenly have to either do

Maybe. But you do lose some transparency and repeatability - it becomes harder for others to understand and use your Dockerfile. They suddenly have to either download or recreate whatever debs/tarballs etc you've used. I think the real problem is that Dockerfiles aren't expressive enough yet. At the very least we need a more user friendly method to run several commands in single layer.