"the leaders of New Classical thought did not want to update Keynesian thinking; they wanted to destroy it"

yup

why ?

" The label ‘Keynesian’ was associated with much more than a belief that prices were sticky and that therefore aggregate demand mattered."

ie the dim buld new keynesians

" Instead Keynesian  became associated with state intervention"

quite rightly !!!!

in particular liquidity traps and fiscal injectors