They had countless detailed surveys to refer to, many of which had been carried out by themselves, or on their behalf.
The repossession and sale of the blocks was hurried through for political reasons and sheer bloody-mindedness, and they just didn't want the facts to get in the way of their short-term aims.
I don't think that 'a large proportion of what they've had to put right would have been preventable with proper maintenance'. The blocks were jerry-built in the first place, by dodgy developers out to make a fast buck out of an up-and-coming area (sounds familiar?) The materials were very poor quality and none of the blocks had a damp course. They're now around 120 years old, and rotten to the core. When I moved out 10 years ago most of the structural woodwork (e.g. lintels and joists) was frighteningly rotten. I remember a ground floor window lintel, a huge piece of timber about 200cm x 30cm x 40 cm, that was so rotten I could push my fist easily through its whole width.
Much as I love the blocks, it's hard to come to any other conclusion than that they're well past their life expectancy, which was probably about 60 years.