Honestly this a thousand times.
Most people farming (who aren't RMT) are simply farming for items they need, there are no common courtesy laws when it comes to mob camps or time spent in them. As much as people may like to claim otherwise it's just the nature of things and people will simply use the abilities that kill / claim the fastest whether it be Blunt Arrow or Bio.
Also in regards to people who are higher level doing this well that's an easy one, Higher level = Faster kills = more items obtained in a shorter amount of time.
However like others have stated, I myself am willing to change camps (barring availability) if I'm simply asked, but another person being there first has no affect on my decision to kill mobs for mats that i need.
I think you're simply reading malicious intent where there isn't any and responding in kind.
