Complaining means that we know what's wrong, but we:

don’t realize we can change it. (We believe we're powerless.)
are too lazy to change it. (We'd rather just complain.)

As a friend, I hate this. Because it’s a lot of work to make complainers realize they can change things. They always push back with all the reasons they can’t, which just reinforces the two points above.

As a colleague, I love this. Because I know I’m powerful and can change anything. Because every complaint is an opportunity. It’s fun to invent solutions to problems, turn ideas to reality, and watch my creations make the world a little better.Then afterward, on a personal note, I can say, “See? Told you it could change.”