Here is my take.....if there is a ton of chit chat on the wilderness calling frequency then it is very likely that a person needing assistance could potentially be heard. If the wilderness protocol frequency was quite and only used for monitoring I would guess that few if any emergency calls would be heard.

I would much rather attempt to break into chit chat than call on a frequency that had no listeners.

I have the wilderness protocol frequencies programmed into my radio and find them essentially unused around here. I have always considered this a great idea with few participants.