Not only, there are more motives to pubish, but attention has certainly a high priority for most...

While I personally have only listened to very few submissions, others really do listen to them. (I don't write songs, yet.) Since many here are hobbyists they want a more or less honest feedback of what others who do the same think . If you're [put your craft here] you can see if another [crafter] did something that triggers you to a "+10" or a "-10" or somthing in between.

If you are a beginner, the judgment of another beginner with about the same type of skills is often more valuable than that of a full fledged pro (depending on his/her mood to descend the ladder to one step lower and higher of your level). If you catch that pro in the wrong mood the feedback's value is zero.

Just for this thread I have read a couple of them feedbacks and all that I have read have goodwill ringing in their tone. I don't go into more detail here. Since I only have read a small sample of vast amount available I didn't see any really negative feedbacks, but some that point to what could be done better (in the ear of that particular listener), most often giving also tips.

But that is common in this entire forum.

Guido

Desktop; i7-2600k, 8 GB mem., Win 10 Pro, BIAB 2017; RB 2017 - latest build
Laptop: i5-2410M, 4 GB mem, Win 10 Pro, BIAB 2017; RB 2017 - latest build