It might depend on how things work out. For instance if Healy becomes PM under such conditions of economic problems he might be able to force through basic reforms on union power which gets a more balanced economy. Hence no swing to the other extreme.
Or after failing with this Joseph wins and being somewhat less subtle than Thatcher alienates so many people that he and the Tories are kicked out after a single term. With a general improvement in the world ecomomy and North sea oil entering larger scale production and not being wasted on unemployment payments and tax cuts for the rich Britain has a more rounded economy and a more successful one. The sense of self-belief isn't totally destroyed, and an acceptance that government can have a role other than cementing the domination of the ultra-rich.
Another possible factor. Healy was by most accounts deeply hostile to defence spending. It could be then that he cuts enough earlier to trigger a Falkland type conflict, plus possibly fails to pay attention like the Tories did OTL. [There are reports the junta was considering an attack about 1978 but the government of the time noticed signs of a build-up and sent a few signs of their own and the junta backed down]. In this case the conflict could come during a Labour government a few years earlier. Britain is still likely to win as it has more power at the time, despite possibly greater cuts, and no Falklands boost for the Tories. [They would still make capital by pointing out Labour neglected the defences but wouldn't get an play if/when Joseph then gets in and fouls things up as OTL in the 80's].
Anyway, turning into a bit of a rant again
but there are so many variables that a Thatcher-type reaction, under her or someone else is by no means inevitable. Quite possible to have a more rational response to excessive union power leading to a much stronger economy and society than OTL. Or failing that a one term excess that alienates enough of the people that the damage done is a lot more limited.