The Shaggs may be the unlikeliest group since the dawn of rock ‘n’ roll to have attracted a cult of hundreds of thousands or even millions of fans, all of whom take their place on different parts of the ironic-to-sincere appreciation scale. Were Dorothy, Betty and Helen Higgin, who comprised this late ’60s/early ’70s trio, so bad they were good? Or so good they were bad, if you want to look down that particular hall of mirrors? Childlike amateurs, or enfants terribles , worthy of the respect