MN is not a free service provided gratis for the good of society, it's a free-at-the-point-of-use service that provides an important function but is ultimately run for income and profit. It is not a registered charity. We, the consumer, pay for it by viewing ads and responding to sponsored content.
Considering the nature of the forum, vulnerable people will post here and abusive people will target them from time-to-time. My feeling is that MN has a duty of care for the vulnerable people and that proper moderation should be round the clock with a lower threshold for banning / suspending members in certain threads.
I wonder if MN could be subdivided into two parts - one for loosely moderated fun, discussion, advice about daily life etc and one for closely moderated support of people with significant personal problems. The support side could be charitable, the other side for profit. This support section would be conceptually like a social media Samaritans / Relate / SANE hybrid with the community providing support instead of volunteers and the volunteers providing moderation and maybe even offering PM support for those who are obviously struggling. Members who don't quite get the vulnerability of others could be banned from one part of the forum but allowed to continue in the other.
Of course, this may impact on MN's revenue stream as MN would have to show any revenue from the charity side was spent appropriately. However, donations, tax breaks and volunteers may balance this out by reducing running costs. It would also be an ethical plus for those running the organisation.