SLF3,
In the first instance what you describe is a good safety culture; if that doesn't exist then individuals could feel threatened.
The second point is that the majority of decisions relating to the 737 Max MCAS were subjective, even some hazard categories. Because these situations rarely have well defined boundaries it is not immediately obvious whether to sign or not sign; nor where the line is - who draws the line - management or expertise.
Furthermore the judgement of pilot contribution in the event of a failure could be critical, thus expert opinion from several sources has to be combined; e.g. technical shortcomings could be offset by pilot action, but if judgement of the pilot's contribution was an over estimate then the effect of a failure could be larger.