"Freebies" or "cheapies" can trigger rather primitive, pack-like behaviour and bring out the absolute worst in people, who in other circumstances might consider themselves quite civilised. Just look at the rugby scrums or even punch-ups in the shops on Black Friday or at seasonal sales if you need reminding how thin the veneer of civilised behaviour is. Another example is the spectacle of the Brit abroad, elbows out, demolishing the help-yourself buffet at their package holiday hotel, and then leaving half of it uneaten on their plate. So no, I'm not surprised that the phenomenon is also seen in so-called "nicer" circles. Typically human, and rather depressing I'm afraid. Much prefer my dogs..
Anger management!!! Help needed.