This option was introduced in 2008 by commit 0d6945b, with no motivation or use case given.

On rare occasions, I have found it convenient for troubleshooting purposes. However, it can be achieved by a location constraint with rsc-pattern=".*" and a rule matching all nodes. It can also be achieved by placing all nodes in standby mode. It seems unlikely to be very useful to anyone besides developers.

Dropping this property would simplify output messages and the set of overlapping, possibly conflicting options that control where resources are allowed to run. (Precedence has to be determined when options conflict, and such a choice will always be somewhat arbitrary.)