Might be because for years british managers like him, Redknapp, Curbishley, Pardew, Big Sam (Even Mclaren pre-england) were media darlings, praised as brilliant, LMA awards galore, always assured of a job if they lost one despite barely achieving anything in terms of top flight trophies. Quick wiki summary of the greatest achievements of the above mentioned.
Moyes - Charity Shield
Redknapp - Fa Cup
Curbishley - biggest was a first division title
Big Sam - best was championship play offs
Pardew - Championship play offs winner
Mclaren - League cup and the Eredivisie and is the most successful of the lot!!
British managers are often trumpeted as the cure all but look how well the lad at Hull as done since he come in.