It is borne of frustration and fear ~ frustration in trying to do things right, only to see others who are obviously doing things wrong outrank us on a regular basis; fear of what that inevitably leads to, which can be summed up in 3 little words: "loss of income". And we all know that if the loss is too great, everything changes, and usually not for the better.
I tell my wife several times a year how difficult it is to work in a vacuum, with little real understanding of what is happening to others. When my visitor count drops, is that happening to anyone else? When my sales drop, is it only me? Or is it the economy at large (which by any definition is tenuous right now)? or are others doing pretty well even when I'm not? It's hard to figure that out when I sit at a keyboard and can easily go hours (sometimes days) at a time without even seeing another human being.
So in additon to learning from others & sharing what we discover, people come here to vent, in part because it's therapeutic, in part because we're looking to find out if there's any company in this misery. Because as often as not, many of us are working in the dark, and in the dark, it's hard to see.
I hope you can ignore the rants, and see them for what they are. Personally, I'm at a point where I'd be thrilled with an entirely new category: "Prospering Without Google", with no venting allowed ... speaking for myself, I'm ready to move on.