I still find much of this debate really interesting.
When we've had 'dodgy' goalkeepers in the past, one of the main criticisms levelled at them was that they didn't instil confidence in the defence. Brad Jones was probably the most heavily criticised for this. Jason Steele was criticised for this for about two years until Shay Given pitched up. The team started keeping clean sheets but I don't really remember Given routinely making amazing saves, or even making many very good saves. He was just a very good goalkeeper - at the time he played for us - who had once been an excellent goalkeeper in his prime years . But he was showing this without really having to do too much - and people spent lots of time saying that he instilled confidence into his defenders.
This season Boro had conceded very few goals - especially from open play - up until we had some injuries. Three of our key players were out, including two main defenders as well as the main ball carrier. But when we were keeping the clean sheets, keeping the goals out, was Bettinelli not instilling confidence into the defence during that period? If he wasn't then surely they would've conceded more goals on account of not trusting him, just like Boro defences playing in front of Jones and Steele did. How could they keep clean sheets and defend so well without a decent 'keeper behind them? And, if they were capable of defending well in spite of Bettinelli back then, why have they not been capable of it in recent weeks?