Woah, mate. I think that way of thinking might be more-than-slightly career limiting.
The community does play a role in the ecosystem you’re buying into. You will most likely need to send PR’s / bug reports in at some point. If the core team tends to ignore bugs/external contributions, it is a point to consider.
Furthermore, if your first knee-jerk reaction to the behaviour you think undesirable in reports is to “limit their reach and upward mobility” I think you need to think seriously about what mentorship means.
If these types of people are in leadership positions, it’s too late and you need to move. If they’re below you, then you need to limit their reach and upward mobility.
Usually fair application of performance standards will flush them out anyways. Often people like that in your organization are shielded by a manager that’s protecting them.