For example, Pie or Whiteflame would like to claim commuter as scum because they are a bitch to mislynch as town, so scum wouldn't keep them alive and would NK them instead if they were town. So, their survival is in itself suspicious, and the protective aspect of the role explains them not being targeted. It has no such benefit for Shining, as town Shining is easy to mislynch (as Pie recently demonstrated), so there's nothing suspicious about him not being targeted for the NK, so he doesn't need to claim a protective role to explain away his survival into late game were he scum. Instead, claiming ascetic if he is commuter is the better choice because it could absorb something like a town vig shot or a redirection of the NK.