I actually believe the opposite to the OP - that the quality of the 'good' stories has actually been improving over time. I think that's because writers now are more aware of the history of erotic literature than they were perhaps ten years ago when the internet was young, and the only bondage literature that was accessible was from quite a narrow perspective. When I look at some of the recently written/expanded stories such as
Group XS, there's no doubt that there is so much more possible now than there was five/ten years ago. That may just be because my tastes are far out into the extremes, but those are my feelings too.
I also agree that even a short email, which takes maybe ninety seconds to create and send, may well be the difference between a writer continuing your favourite story, and them giving it up as too much effort. So be selfish for once - encourage more of the stories you love, and let a writer know!