I'll add my two penn'orth. It might not last long before it's deleted.
I see a few different functions for the 'Alert' button. I'm not suggesting that they are the only ones:
1. The most important use, IMO, is to alert Mods to potentially offensive or illegal posts. This avoids offending any potential posters and avoids the site creating a biased or prejudiced viewpoint, allowing and encouraging increased contribution to the site as a whole, from a wider variety of contributors.
2. Another valid use is when abuse or insults or potentially libellous comments are used against another poster. The use of the alert function prevents a degeneration of the discussion into petty squabbling.
I'd be quite happy to trade insults with any poster, but it's not amusing, entertaining or helpful to other posters.
But I, personally, am not prepared to accept insults, abuse or inaccurate accusations without some action.
3. The alternative use is to avoid potential hijacking of a post. Sometimes, this is by innocent newbies. Other times it is by experienced poster(s), occasionally, inadvertently causing the thread to wander off-topic.
Unfortunately, sometimes it is by experienced posters wading in with insulting or abusive comments, trolling for petty squabbles or intentionally trying to cause the post to veer off-topic. Sometimes, resulting in the whole thread being deleted.
This is when the use of the alert function can be abused, or not used when it should be, and when over-reaction, or unfair deletion, by Mods is most likely to occur.
In the main the Mods have maintained a reasonably distanced view and taken appropriate actions, some more than others. Although without feedback it's difficult to assess.
I think however, there are occasions when the Mods are unfairly influenced by the experienced posters. Perhaps because, sometimes, they are one and the same.
Surely, in the cause of fairness, any poster, who is also a Mod, should be excluded from moderating in a topic, once they have contributed, as a poster.
But also, IMO posters should be assessed as to their usefulness to the site, not only in their contribution in the DIY sections, but also in their quantity or quality of the posts in the GD forum. If the experienced contributor is regularly and continually posting abusive comments, then their usefulness to the site must be wearing very thin, surely.
Their continuous abusive contributions must be discouraging new membership or disaffecting some current members.