Nothing pisses rock fans off worse than the lead singer of their favorite band being replaced.

This happens across genres, but it’s most common within hard rock — pop, country and R&B vocalists’ departures are usually a precursor to their solo efforts; very rarely does their band continue without them. Hard rock and heavy metal fans, on the other hand, see their favorite bands as a cohesive unit, so when a singer leaves, the rest of the band oft

Source:
http://blogs.dallasobserver.com/dc9/2011/11/the_top_ten_all_time_best_repl.php