Historically, the --all parameter was added to reprocess software releases which consist of locally modified git repositories and the only way to be sure to have the same software release on runner0 and runner1, if user had modified their local slapos.git repository on runner0, is to force the reprocessing of the software release on runner1.
Nowadays, a software release should not be updated in place, and the good practice is to clone a second time the repository containing the software.cfg if we need to deploy a second software release or a second version of the same software release. Or better: use URLs to deploy software releases. So forcing the build of the software release on runner1 doesn't make much sense anymore, in my opinion. Except if we develop a software release, but in this case what is built on runner1 is not important (only the new SR code is).
Reprocessing of all software releases is a risk because it depends on external services. And if these external services are not avialbale, reprocessing can lead to no resiliency at all.
Therefore we remove the --all paramater when running slapos node software.