I have had people ask me when I decided to become a writer, or what made me want to be a writer. I did not have much of an answer since I cannot remember ever not wanting to write...even before I could read, I wanted to write.
I have come to realize I was born a writer who, at some point took up the challenge.
And a challenge it can be. I tend to agonize over every word on the page, frequently trying multiple variations before deciding that I have the best one, only to come back later and change it three more times. That is being a writer to me.
As for rewards, after spending countless hours writing, rewriting, editing, rewriting, redrafting, did I mention rewriting? and then finally allowing someone else to read my new treasure I get the response 'it was good'.
GOOD? What does that mean? Writing is a never ending quest for perfection in prose, and authors crave feedback so they can learn to write better: at least real writers do. With feedback like 'good' we are left with no idea how to improve our work.
I think most readers are afraid they will hurt the author's feelings if they offer criticism or they feel unqualified to offer any.
If an author is afraid of having their feelings hurt, they should never let anyone else read their work. As for being qualified to offer a critique, if you can read (or understand when someone reads to you) you are qualified. Not only are you qualified, you are owed the opportunity.
Writers write to be read. If they can't reach their audience they are wasting their time. All real writers want to write better and it is through constructive feedback that that process happens.
I don't expect readers to correct my grammar or spelling...that is my job, but comments like 'this sentence doesn't sound right' go a long way toward polishing the final work.
Comments such as 'I didn't feel like this character would do that' or 'I felt unsatisfied with ending' will help the overall product get better.
I look forward to having my stories read but I look forward more to hearing how my stories make my audience feel. I promise, you won't hurt my feelings but you will help me become a better writer.