Doesn't mean performance of associated music chronicling or arising from our past should be suppressed

Nobody has suggested that it should, so this really is a red herring. In any case, there are precious few songs celebrating child labour or transportation, which would be the analogy with the racism of the minstrel show. There are songs that celebrate hunting, of course, but even that's not a very good example from your point of view: someone who found hunting offensive - or who thought their audience was likely to - would probably choose not to sing Dido Bendigo, there being after all plenty of other songs to choose from. Why then the insistence that Morris sides who black up should continue to do so, and that anyone taking offence should be ignored?