I'm about the most critical person ever when it comes to Riot's communication, but I have to disagree with you on the idea that Riot avoids criticism. Think about this as if each Rioter is a separate person (which they are); as a general rule, there are a few topics that a particular Rioter can't really reply to in a meaningful way:
- Complete outright negativity and anger
- Subject matter not pertaining to the Rioter's area of expertise
- Critique in hundreds of tiny threads when discussion is already happening elsewhere
I will agree that Riot does drop the ball at times when it comes to communication (Cassiopeia rework: "oh right sorry we decided months ago this is no longer a thing, oops probably should have told you"), but this affects both things they are doing well and things they are doing poorly rather than just criticisms.
I feel like the issue you're touching on is more due to risk aversion than not wanting to deal with critical feedback. It seems as though Riot is increasingly reluctant to experiment or even really dedicate specific resources to regional engagement, but I don't think that's because they ignore feedback.