I think the main thing dragging down the existence of hero groups is the lack of player settlements and permanency. In the mod it was far easier to justify setting up a safezone as it was unique and could act as a genuine base, this is so much harder to do in SA and you have to use a pre-existing settlement. As people have said above though there are some survivor groups.
Innocent until proven guilty!
But in all seriousness if the GMs keep on ruling that someone is Not Guilty in reports then its probably whoever keeps on making the reports that is at fault. But interesting point though!
Let's sit around a big old fire and sing kumbayah then yeah? Its an apocalypse you're not supposed to get around without being messed up. Robberies can provide a lot more RP than you'd think. Let go of the gear attachment and enjoy the RP you're getting, you might just enjoy it.
Travel in numbers, carry a big gun, stay out of triangle, anything. Its extremely simple to not get robbed.
If you go back to the beginning of the post I literally said that I don't mind getting robbed as long as there's good RP in there. I don't like the robberies where the guy puts a gun to your head, cuffs you, takes your stuff, tells you that "This is how the world works now, just wiggle" and bolts it. If I get robbed I would want to feel actually intimidated in character not just frustrated. Make it interesting, make it fun for both sides is all I'm saying.
I reckon that about sums it up. Robberies can be some of the best or worst experiences in DayZRP.
+1 To the above posts. Knives ain't normal although I do agree that it is weird they would call him a bandit simply for carrying one. But I can understand not wanting a man with a knife in his hand to run up to you.
You could also watch some of series made on DayZRP, people like Psisyndicate and DDG are big Youtubers who are making series whilst there are lots of smaller ones here too (and others that I probably forget )