Harry Lennix, an actor who has frequently worked with Taymor for almost 20 years, tries to answer the question in The Huffington Post:
In my opinion, the producers of Spider-Man have found a convenient whipping girl to bear the brunt of any woes related to the production. They seem to have absolved themselves from accountability for the show’s production while reaping the benefit of the publicity surrounding the absurd decision to jettison the creative visionary behind it. In their minds, the fault couldn’t possibly lie with an untested Broadway producer, or the two all but absent rock star composers whose notoriety is derived from a completely different medium. Rather, they are eager to blame the female director whose last Broadway endeavor resulted in nothing short of a transformational experience for audiences around the globe. (Let alone the phenomenal success of The Magic Flute at the Met or her glorious productions of The Green Bird, Juan Darien, and Oedipus Rex… I could go on.)
While Julie is being thrown under the bus, the producers are enjoying the Pyrrhic spoils of their victory: the show remains one of the top three highest grossing productions on Broadway. For theater professionals not to defend her tremendous accomplishment, productivity, and prodigious artistic abilities does a disservice to all theater artists. This is a betrayal to the true spirit of the theater.
In theater, one rises or falls as a company. That’s the tradition and the standard. In this case, the producers are allowing a consummate artist to twist in the wind while abetting the perception that Julie Taymor is the person solely at fault for all that may be wrong with Spider-Man. Any logical assessment of the situation here reveals a few stunningly simple facts. First, any financial woes are due to years of repeated starts and stops trying to get this production off the ground. This is in no way the fault of Julie Taymor. Second, as far as I know, Julie has never rigged a harness for an actor, nor ever pulled up the curtain to open a show. Accidents happen on stage. Sometimes they are inevitable. However, the persons directly responsible for mitigating such circumstances are stage managers and stagehands, and the ultimate responsibility rests with the producers. To allow Julie to be portrayed as somehow at fault for these events is simply wrong. Further, the fact that the music and songs may not be complete is, again, the responsibility of the producers. Theater directors aren’t hired to travel the world with U2 or beg two rock stars for lead sheets.