Since uninstalling software can be broadly considered as part of software installation, I propose that we make both software-uninstall and uninstall tags synonyms of the software-installation tag.
Similarly, since "uninstalling a system" doesn't make much sense as a term and since it can be broadly considered as part of system installation, I also propose that we make system-uninstall a synonym of system-installation.
I believe it's better that we don't get rid of the tags completely, rather make the above synonyms, as it seems that quite a fewmany users use these tags, and even if we remove them, chances are that someone will create them again.