why do they boo bruce reville

They are not actually booing Bruce Reville. Fans are often loudly chanting "Bruuuuucccceeee!" which sounds like booing but is actually cheering for him. This chant originated among Brisbane Lions supporters and has become a positive affirmation rather than negative booing. Any perception of booing may be due to misunderstanding or the sound of the chant, but it is meant as support for Reville rather than criticism or displeasure.