I think that one of the main problems is that interaction and RP take soooo long. In the time it takes to type out "you interdicted me - what do you want", your shields are down and you're sucking space. Most traders simply won't take the chance that a CMDR who pulls them out of SC isn't going to toast them straight off. Voice comms would be great, but there isn't really a system for that as yet.
It'd be great if voice comms were automatically on (an opt-in option in config maybe) between whoever is in same "instance". That goes without notion, that the comms should be robust enough to actually work 100% the time.