What is the most important quality of a product designer

Depending on what questions you ask and who you meet, user research can be very good or very bad. But I still think user-driven research is the most important of the four.

I could write a book on this. I have been in meetings where technical decisions are glanced over, yet the color of a button has caused a full meeting meltdown. Designers need to be able to communicate their concepts clearly and articulate why some suggestions from non-designers won't work.