...there is NO UNIVERSAL lighting solution that is appropriate for ALL situations!
Very true. It's highly dependent on the situation and/or the desired look. Obviously the StoFen works better for the situations the OP described (crowded indoor events, dark walls/ceilings, etc) than for outdoor, distant shooting.
As far as indoors goes, each modifier (diffuser or otherwise) has a different look, and can be used or misused according to the photographer's whim. Like you said, there is no one right answer.