As i said in the other topic, if people can PL, it'll do, but don't mean you require to PL.
Level synch it's a great feature in a world where you can level only in party, but since in this world you can level solo too, allowing PL isn't a game breaker. If you find a friend willing to help, ok Pl, otherwise don't. The end.
We all remember FFXI don't? And people PL. A more restrictive claiming don't stop people PLing, let's face it