In some ways, Mark, it HELPS people because they then see a REASON behind their spouse's sudden uncaring behavior. You can also then begin to see them as an addict, which of course they ARE at that point (although it doesn't excuse the initial decision to have an affair).
I know it sounds weird, but it some ways, it helps. I mean, think about it: what word is the ONE word you see more than any others in LBSs' posts???
"WHY"
The discovery of an affair -- as painful as it is (and it is, horrible) -- DOES go a long way in answering many of the "why's".