Webster defines constructive  as this:  promoting improvement or development 

and criticism as this: the act of expressing disapproval and of noting the problems or faults of a person or thing : the act of criticizing someone or something

: a remark or comment that expresses disapproval of someone or something

: the activity of making careful judgments about the good and bad qualities of books, movies, etc.

Not all criticism is constructive. But what does make criticism into constructive criticism? 

My humble opinion is the way criticism is delivered. "Your story ." Not helpful. "Your idea is intriguing but was lost in your over use of ." Helpful. "I liked the plot, but couldn't identify with the characters." Also helpful. 

I'm not one of those strong people that says all criticism is constructive to them because they take what they need from it and ignore the rest. 

I'm thinking of this because I read some criticism about something I did, but the person with the issue never went to me and told me what I'd done that needed improving. Not helpful.

I, being the overly sensitive loser I am, cried and told the group I wasn't going to help any more. 

I'm one of those people who says that if you never try, you never fail. Other people say if you never try, you've failed. Maybe there's a good middle ground in there somewhere?