Liz has also been a long standing NPC one of the few that helps outlanders. Removing liz removes "knuckle bone" healing potions from the area as well. The temple without Liz.. well its just not the same temple.
Anything that takes away the resources new players or new characters can draw from is not something I like.
You forgot about ol' Zachy?
There's no reason to think that the slums priest wouldn't help outlanders, or offer the knucklebone elixirs. And yeah, I know it wouldn't be the same temple, and I find it intriguing. Plus, Liz is one of the biggest draws to the Outskirts and I'm curious if the Outskirts would continue to be as populous as it is now, if she left.
As for your final statement, I feel like outlanders are overly-sheltered and overly-coddled in the Outskirts, and that's partly what leads to the strange un-Ravenloft-ish, outlander circus behavior that we see occur there, so often.