Having read their letter, they don't appear to be saying anything other than in general we disagree with what you are doing.

I'm with Gareth on this one, the time for these gentlemen to have spoken up was when they were "in the chair". Maybe their advice should have been a bit better, irrespective of how unwelcome - didn't happen of course, because at the time their major considerations were safeguarding their index linked pensions and their knighthoods.