Its could be argued that a lot of people find it easy to complain, but if you really want to make a change than you need to provide constructive criticism. I regard complaining as simply saying what is wrong with something in your opinion, so what you do not like. But what does this actually achieve apart from letting off steam? The hard part is actually figuring out how do make something work better for the benefit of yourself and others.
I am good at providing constructive criticism rather than just complaining, it is often how I open the door into getting paid work. When it comes to accessibility and disability issues, I can often be on auto-pilot as I point out to others what I see. If more people chose to give constructive criticism rather than just complaining I believe the world was indeed be a better place!