The only difference is that in PvP, the higher-level content is mixed in with the lower-level content. So if you need better gear to do the higher-level content, then you can never do *any* content. (hence, PvP's current well-deserved reputation of being very newcomer unfriendly)
You're right, RWZs are a mixed bag of lowbies, PvE and F2P. Working as intended.