ものだから as an excuse — is it always making an excuse, or can it be neutral cause-and-effect?

Question

Every example sentence I've seen for ものだから sounds like someone justifying themselves: 「電車が遅れたものだから、遅刻しました」— 'the train was late, that's why I was late.' Is this grammar inherently excuse-flavored, or is that just a coincidence of the textbook examples I keep running into?

Accepted Answer

Not a coincidence — ものだから really does lean toward self-justification / explaining away an unintended or slightly awkward result, spoken to someone you feel needs the explanation (often apologetic in tone). It's close to ものですから (more polite) in that sense. Compare with ので, which is neutral and works for ANY cause-effect, good or bad, formal or casual, no excuse-vibe required. So you could say 「頑張ったものだから、疲れた」(a bit odd — no need to excuse being tired from hard work), but 「頑張ったので、疲れた」is completely natural. ものだから really wants an excuse-shaped situation.