Bree, that's more the fault of the story. You couldn't even care for John Cusack.
However, that works for film and literature. But I don't understrand why anyone would want to write a musical with a protagonist that is detestable.
It worked in CAROLINE, OR CHANGE mostly because she goes through a triumphant, dramatic change. Rob goes through one - but is it really one you care so much about? And, is that change ULTIMATELY a plot?
"I know now that theatre saved my life." - Susan Stroman