When an actor in a show literally tells the fandom that they should create the desired ending of their own in fan work (namely fanfiction), and so many people are extremely dissatisfied and upset with said show… you know that you have a problem. Or you should, at any rate. Growing up, I read fanfiction when I was a child — I am dating myself by even allowing this sentence to show up on my blog, but I digress — and the legality of it was so… questionable then (definitely not advocated with by the Fair Use doctrine so long as the creator does not make any money off of it) that we wrote long disclaimers at the start of every single one of our fanfics begging the creator of those characters and that world not to sue us for daring to write that fanfic.

You should not have to write your own happy ending because your favorite show botched the entire landing.