I would agree with you there - though notably "Through a Glass Darkly" whilst shittier than OTL over all does have hope spots - Noel Skelton would likely have been really rather good as PM, Anthony Nutting would have been poor due to inability to execute policy not policy itself (similarly to Heath) and Duff Cooper would have been far better domestically than Eden to my mind at least (though this would be backed up by a far more aggressive hostile policy if a more measured one, perhaps). Mason onwards is more conventionally "like OTL but worse" however, but again Collins and Drling are bad but hardly dystopic. It's OTL but worse, but also to an extent just "OTL but different".
If I'd wanted it really bad Powell would have been the Thatcher analogue.