Loathsome memories are super easy go get. Just leave a quest up while you are leveling an alt job in Bozja. By the time you reach 80 you'll have more than 50 memories easy.

The problem is the Timeworn Artifact. The in-content method of running Derubulum is tedious, boring, unrewarding and takes a lot longer than the alternative of just spam PoTD. Derubulum should be dropping at the very least 3 Timeworn Artifacts to be worth running, or be outright revised so that it isn't a boring snoozefest. I run Derubulum 2 days ago after skipping it for 2 months thinking that maybe my bad opinion of it was affected by burn out, but no, it's just plain bad no matter how you look at it.