BlackToad: "Should we protect" or defend the members that appear to be chronically laying down negativity, intentional or not?"

It should be sufficient to rebut a certain unfounded negative (or positive) aspect once or twice. If the poster continues to bring up the very same point over and over again, we have an Agoracom Rule against it. I would also not tolerate negative or positive claims without good reasoning, like "I have a gut feeling that the share price will go up/down today" or something more subtle.

Bottom line: I would accept everything new that has good reasoning attached. The reasoning might turn out to be weak on a second look, but we'll find this out soon, and this is what this forum is good for.

Oh, and then there are people who seem to be more negative than others. This might actually be beneficial for us as they can find weak spots earlier and better. But of course this does not apply to each and every poster here.