Gotta Love Marlon
But I am not sure I ever knew fully why until Norm pointed me
at this wonderful analysis
by Joe Queenan - short excerpt, which expresses the basic idea most clearly (but read the whole thing at least for the reference to Dean Martin!):
1972 was a banner year for this master of self-sabotage. In The Nightcomers, a weird prequel to Henry James's The Turn of the Screw, Brando winds up sporting matching arrows protruding from his head. In Last Tango in Paris, a once-controversial film that now merely seems stupid, he gets gunned down by a perky sex kitten whom he had been mauling fore and aft for the previous few weeks. Stalked and gunned down in the streets by tacky, classless gangsters in The Godfather, a stricken Vito Corleone later falls down dead while impersonating Dracula. Brando is probably the only major star in motion picture history to die in three different films in three different ways in a single year. Hats off to him for the arrow adios.