Criticism is one of the ways in which knowledge advances. It is a type of thoughtful feedback (and subsequent dialogue) that helps expose blind spots, identify misunderstandings, provide alternate explanations, or uncover errors that others cannot see or are unwilling to acknowledge.I agree with you. I put much of the blame on insecurity and mistaking respect for people with not making anyone uncomfortable. When people are insecure or unconfident they often take criticisms of ideas, plans, results, etc. as personal attacks. Then misunderstanding of don't be "dis-respectful" to people comes into play.
Without criticism from others, we are unlikely to challenge our own thinking or escape the comfort of self-satisfaction. We fall prey to the confirmation bias and accept information that confirms one’s views and reject all information that does not. We also develop a love for the status quo. Criticism is rejected without consideration and attributed to people who are simply uninformed or who suffer from professional jealousies.
The outcome is blocked information flow, which is the opposite of what we seek to achieve in Lean management.
I have written about this several times
Respect for People Doesn’t Mean Avoiding Any Hint of Criticism
Building a Great Software Development Team, a significant part of which was hiring people that would debate ideas without becoming overly personally defensive.
And those posts link to more related posts. The retreat into criticism of ideas is dis-respectful is a real problem for management improvement. Usually there are plenty of other more severe problems, but if you are doing well and getting rid of common failures to manage the organization as a system, experiment and base decisions on data (in many ways) you are likely to reach a point where the fear of debating ideas common in the USA becomes a serious problem.
Related: What Does Respect for People Actually Mean? - Disrespecting most people in order to avoid confronting one person is not good management (or respect for people)