I'll have to look into this. My immediate assumption is that we don't want member systems overlapping, which could happen if the member system is on a Composr level (rather than Conversr) and someone chooses to use a different forum driver (e.g. PHPBB) which also has a member system.
By keeping the member system within Conversr, this ensures Composr doesn't have two member systems (because when picking another forum, Composr will use that instead of Conversr).
I have no plans to change this functionality at this time without a very good reason as it would require a lot of core modifications. As a workaround, admins can install Conversr but hide / disable all of the forum aspects of it and just use members. This is what I do on one of my sites.
While Conversr refers to our Member/Forum system, you can already remove the cns_forum addon leaving just the member system. If you then want this to integrate with another member system without actually using a forum driver, there are the user_simple_spreadsheet_sync and user_sync non-bundled addons that allow programmers to setup batch jobs to keep these systems in sync.
By keeping the member system within Conversr, this ensures Composr doesn't have two member systems (because when picking another forum, Composr will use that instead of Conversr).
I have no plans to change this functionality at this time without a very good reason as it would require a lot of core modifications. As a workaround, admins can install Conversr but hide / disable all of the forum aspects of it and just use members. This is what I do on one of my sites.