Remember when New York became a no-PvP system? Remember what happened to NY then?
No one RP'ed in NY. Or rather, RP became very one-sided. Jumping to NY became quick fix out of a battle. Smugglers would just waltz about, poking fun at the lawfuls because they couldn't do anything about it. Unlawfuls did the same. There was no risk of death anymore. In a situation where a pirate could talk his way into escaping (or get blown up), the pirate no longer has to worry about staying out of the system for four hours. The level of lolwutters stayed the same (possibly increased), and the level of RP decreased.
In Freelancer, RP cannot exist without PvP. This doesn't mean that RP requires PvP, of course, but most of the time, it's necessary.