Well said, 'GUEST JC'. Although some of MacColl's political views may be open to criticism there is no doubt that he championed many worthy causes during his lifetime and was not afraid to be outspoken or to fight against the concensus.
Nevertheless, I am convinced that most of those who seek to criticise MacColl don't really give a toss about his politics or his name change (as JC so rightly points out no-one ever criticises Robert Zimmerman for changing his name)- they hate him because HE DID NOT ENDORSE THEIR MUSICAL TASTES; it's as simple as that. Again, as JC points out, MacColl believed that folk song was a serious art form, in its own right, and should not be mindlessly colonised by the latest fads in contemporary commercial popular music. For the record I believe that he was absolutely correct in this respect.