I think you'd be hard pressed finding anyone being a professional aviator who would suggest mistakes are OK and to should be tolerated.
The view I expressed way back at the start of this thread was that being human we make mistakes and there but for the grace of God go I, meaning that no matter how rigorous the training or robust the safety management system people still make mistakes.
Herein lies the problem. Firstly determining the motivating force behind the mistakes made, and secondly ensuring these errors (latent or active) do not occur again.
You will never stop errors being made where the intention has been to violate an SOP or regulatory requirement.
The introduction of SMS's, LOSA's, and behavioural marker systems can moderate deviant behaviour, however having said that it is still reactionary and cannot respond to the undesired behaviour till it is evident.
No pilot flies without making errors, they may be small in comparison to altitude breaches but nevertheless they are errors and Keg you are quite right in saying they should neither be tolerated nor promoted.