"MacColl was a performer and entertainer."

He most certainly was - a natural singer however - he wasn't - compare:

Dirty Old Town - Ewan MacColl

Dirty Old Town - Luke Kelly

Dirty Old Town - Paddy Reilly

James Henry Miller came up with some great songs, powerful songs, written in the traditional folk idiom - he never purposely wrote a "folk song" in his life (said so himself), he wrote songs about folk and many of his songs were taken up and became "folk songs" in exactly the manner that Jim Carroll has described as "the process" (Which has nothing to do with the song writer, but everything to do with how the song is received by others), his most critically acclaimed song, "The First Time Ever I Saw Your Face", is most definitely NOT a "Folk Song". Not the first or last songwriter to have his own material performed better by others - Bob Zimmerman is another icon who produced great material but was no great shakes as a singer.