Interesting views, I had a feeling this would not be considered a cut and dry "no brainer" decision by some here. As such it is questionable whether the MAA was right to go so public on this - now the scope for a debate on its importance has effectively been taken out of the decision makers hands and it has become a political/red top presentational issue.
Presumably they have done the numbers on risks and usefulness of something like ACAS and are confident that they have scored the trade off correctly.
I hope so.