The fundamental issue is it becomes extremely difficult for people who haven't cleared the encounters to get pug groups as time goes on. I had someone come back to the game shortly before things got shifted to DF and they were in a queue for well over an hour before they gave up trying to just get into Sophia EX for the first time. We ended up having to get enough people together in the FC to clear it for them.

Now you can argue that there is nothing stoping a player who hasn't cleared from forming a practice party in the Party Finder but there really is nothing stopping people who have cleared from doing the same for a farm party and there is generally more people interested in farms than clears.