I have never put anyone on ignore, ever, in any forum, as far as I can remember. And I don't intend to. Just an interesting thought. (Maybe there was one exception, I don't recall that I banned that person or just thought I should have.)

Ranters are a potential source of positive energy, all you have to do is turn them around. It's not easy, but it is possible.

Dissenters are essential to any organization, because situations are always subject to radical change, in which case the people most ready for the change are not those who supported the status quo, but those pushing for an alternative. They have thought about how things might change.

There is an Internet tradition of impoliteness. It is bracing and not always comfortable, but it works, in that it allows a frank and sometimes over-frank expression of views and attitudes. If you succeed in eliminating this element of rudeness, a lot of the energy of the Internet goes with it.

Most people, even me, are capable of rational conversations at least at times. The way to solve the problem is to understand where the dissenters are coming from. You can't do that if you ban them. You are more likely to create an ever-shrinking circle of comrades who are judged good enough for your company.