Just thought I'd speak for the people on the lower leveled range who have a different opinion than dualheart. Sure, I occassionally buy an OSI leech, but when I'm looking to do that dungeon I really don't care if it's in a leech party or not. All I want to do is get it done, and having leech parties makes that so much easier. Also, it helps newer players learn about what they have to look forward to. Personally, I can't wait for the wolf spirit protection party skill thanks to seeing it in an OSI leech. As for helping out with lower dungeons, I have used PC before to get salvage materials, usually without any body I'm helping, and would rather not see that disappear.
Besides, there's a certain amount of pride that comes from soloing a dungeon that used to be impossible for you, and an even better feeling in destroying something that used to kill you repeatedly (like those blasted spiders outside of PC).
I'm only speaking for Quill, but from what I can see, I'd much prefer that the situation doesn't change. As for dualheart, maybe you can find a guild with some people around your level? Seems to me to be the best solution. Also, if you do wind up in a leech party, just kill random things for the fun of it. It's not like you are being forced to sit down and do nothing.