pe1er:
Since in most cases all I want to say is 'good story' or 'nice story' or other words to the same effect, I appear to be banned from commenting in most cases!
On the other hand it is irritating on some other sites to read long strings of comments that simply say 'good story' or 'nice story' or other words to the same effect!
Just to add to what PinkAngel has already said, the idea behind story commenting is three-fold, Firstly, almost all the authors, who generously provide their works for free, like to receive some qualitative feedback. It shows that people are actually reading and engaging with what they have written. Secondly, it's interesting to read the comments that are made by users of the site in their own right in addition to the stories themselves and lastly, they provide extra information to would-be readers in addition to our own story classification info.
I would suggest that if someone feels inclined to only write "good story" all the time they simply ask themselves why did they consider it a good story, perhaps it appealed to their specific kink or they thought the scenario described was well articulated, or the author's imagination appealed to them. I could understand the difficulty if people were being asked to comment on most of the stories but with a requirement to comment once every 500 stories read in order to maintain unlimited access I really don't understand the problem.