"Wait, you have one talk about this and he's cured?"
I don't think OP actually said 'he's cured'.
I think she said "he's finally agreed it's time to sort it out" which, given the way the thread has been flowing, seems much more likely to mean something like 'he's agreed to seek therapy' and/or 'he's agreed to try' and/or 'he's agreed to pee elsewhere, while going to counselling' etc ... doesn't seem so likely to mean 'he's cured'.
"if all it took was one comment on the situation to make him stop completely"
I don't think the OP actually said 'he's stopped completely'.
I think she said "No sink pees yesterday" which, again given things discussed in the thread, could simply mean that he peed in a potty or bottle or something, instead of the sink, to show that he had really meant business when he had agreed that it was time to sort it out.
"now a bunch of random MNers say it's grim, he listens and hey presto"
I don't think the OP actually said 'hey presto'.
I think she said "Think there's hope." Is that not a positive thing?
On the other hand, she did also say "Success" That too seemed to me positive. I took that to mean 'success at them talking it through and agreeing that something had to be done', not 'success at them talking it through and him being miraculously cured'!
Others have obviously taken OP most recent post in an entirely different light. Maybe I should go back and read the whole thread again. No ... can't be bothered .... 
Good luck with this OP ... no matter what way round that "success" should have been taken!