In particular, Google found that psychological safety is a key component of successful teams.
Indeed, I think in an environment where rudeness is the norm, it's much harder to get people to share negative thoughts. Sure, you'll have a few alpha-dicks who will say whatever shitty thing that comes to mind. But most other people will just keep their lips buttoned because they don't want to deal with critical, sarcastic comments.
If you want real, long-term organizational improvement, you have to create an environment were people are willing to share problems and concerns without fear that they'll get insulted or blamed.
One great example is Toyota's culture of continuous improvement, which helped them go from post-WWII decimation of Japan to the world's dominant carmaker. They're explicit that "respect for people" is foundational. A good book here is Rother's "Toyota Kata", which goes into Toyota's culture and people-management practices.
Another is airplane safety. For its ubiquity and technological complexity, flight is amazingly safe. But this requires a culture of deep, thoughtful honesty. Sidney Dekker's "Field Guide to Human Error" explains how much this depends on creating blame-free contexts, how much it requires a deep respect for people. Without that, people will a) blame others, and b) cover their own asses in an effort to avoid getting blame. That muddies the waters enough that you can never find and fix the systemic problems that caused bad outcomes.
TL;DR: If you really want people to share negative thoughts, you need positive, supportive environments.