In some configurations parameters containing both a name and an email address can cause problems. It can be difficult to have these escaped to the satisfaction of all tools in a build chain. Turning this setting on allows these parameters to be omitted.
E.g. parameters like this will not be created:
-DGERRIT_PATCHSET_UPLOADER="Joe Coder" <jcoder@some.where>
Triggers configured before this setting was introduced will have this unchecked, giving the same behavior as before by creating those parameters.