" Defeatist maundering that they will be deleterious to the working class is to be expected.."
Its perfectly obvious that Brexit "will be deleterious to the working class" because many thousands more will lose their jobs and many many thousands more depend on them.
"It's an elementary mistake to assume a change like this will not trigger lots of subsidiary changes..."
Except nobody is making that "elementary mistake" . Its patently obvious that those "subsidiary changes" aren't going to be in any way positive as you assume, because there exists no means at all: neither mass movement nor political vehicle to drive towards any such beneficial change even if it could be obtained. On the contrary the majority of the brexit vote like its political representation is right wing, so you are actually travelling in the opposite direction. On mitigation of the effects of the disaster, Corbyn is actually your best shot, but hey, you've already pissed on that firework.
"Defeatist maundering..."
Listen to yourself... you've already adopted the Faragist wartime "plucky little us beset on all sides" propaganda model... "Defeatists"...deary me... whats next? something more emotionally exciting...like the "...enemy within"?