For me... - learning how to solve real-world problems using software - sharing ideas and reflecting my perspective in the conversation - understanding how others think about SW topics, more learning - criticizing decisions in order to improve my critical thinking skills and knowledge - getting feedback from my own ideas to see how well they stand up
I realize that some of these are somewhat redundant, but I feel they differ in nuance. In general it is about _improvement_.
Also, some people are just way too sensitive and need to realize that an attack on one's idea is not an attack on oneself. I have general respect for all people, but I might think your idea is stupid.
The best thing we can do is make sure we do our best to absorb hostility and respond with objectivity.